Laser selective melting technology is widely used in various fields such as aerospace, aviation, ships, transportation, biomedicine, etc. due to its advantages of large forming freedom, high forming accuracy, and controllable surface roughness in the solid part forming process. Due to the large internal temperature gradient caused by the rapid melting and solidification process of materials under the action of the single laser beam, it is easy to result in uneven structural density, high porosity, high residual stress and poor surface quality of the formed parts. Therefore, referring to the current multi-beam laser selective melting technology that uses multiple mirrors to diverge multiple lasers for selective melting and forming, a multi-beam selective laser isometric follow-up scanning melting and forming strategy is proposed. This strategy regulates the dynamic state of the molten pool through the coordinated action of multiple beams along a certain motion trajectory and time interval. When the main beam performs melting scanning, auxiliary beams with a specific phase difference of each beam synchronize and follow, forming a controllable temporal and spatial superimposed energy distribution. The power of the auxiliary beam is set to 60% of that of the main beam. This simulation experiment takes TC4 titanium alloy as the research object and analyzes the thermal mechanical coupling results of laser path scanning under different time and space characteristics through numerical simulation. The feasibility of this strategy is verified and the changes in temperature field and stress field and their influencing factors in the actual forming process are predicted. The results showed that by controlling the space-time characteristics such as scanning path, phase difference and scanning rate of multiple beams, the residual stress in the isolated region decreased by about 20 MPa and the residual stress in the multi-beam synchronous re-scan node reached about 870 MPa. Under the change of spatial characteristic scanning strategy, the residual stress decreased to 760 MPa. Therefore, it can effectively reduce the cooling rate of metal materials, superimpose melting effects, fill gaps, improve structural density, improve surface quality and reduce residual stress.A multi-beam laser isometric follow-up scanning selective melting forming strategy is proposed. Based on the multi-beam selective laser melting technology (Fig.1), TC4 titanium alloy was selected as the research object and a finite element model is established(Fig.3). The selective laser melting forming and multi-beam Selective Laser melting forming methods are compared through numerical simulation and simulation experiments for analysis.(Fig.4) Temperature (Fig.5) and stress (Fig.6) were predicted, and the temperature field distribution and residual stress distribution in the joint area and isolated area under different forming strategies are compared. The residual stress and deformation in the joint area are controlled by optimizing the scanning strategy.Due to multiple laser re-scans in the splicing area, the forming quality of the splicing area is poor. The cooling rate and temperature gradient of nodes within the isolated zone are not significantly affected by the scanning strategy. For the splicing area, compared with the basic scanning strategy, the cooling rate and temperature gradient are significantly reduced. In the same direction isometric follow-up scanning mode, using the spatial characteristic scanning strategy results in a larger space for heat transfer in the Y direction of the melt pool, leading to an increase in the cooling rate of the joint area. On the basis of temperature field analysis, the influence mechanism of stress evolution process in multi-beam laser melting forming under the scanning strategy of time and space characteristics was established and a method for controlling residual stress was proposed. Compared with the basic scanning strategy, in the inward (outward) symmetric equidistant follow-up scanning mode, the residual stress of the multi-beam synchronous re-scan node is as high as about 870 MPa. When using the spatial characteristic scanning strategy, the residual stress in the isolated area decreases by about 20 MPa(Fig.6). In the same direction isometric follow-up scanning mode, changing the spatial and temporal characteristics separately does not have a significant effect on the residual stress changes in the joint area.By controlling the space-time characteristics such as scanning path, phase difference, and scanning rate of multiple beams, the residual stress in the isolated region decreased by about 20 MPa. Under changing the spatial characteristic scanning strategy, the residual stress decreased to 760 MPa. On the basis of using mature process parameters, the quality of the formed parts can be improved by optimizing the scanning strategy. By selecting the space-time characteristic scanning strategy between multiple beams, the residual stress in the joint area can be reduced while controlling the residual stress in the isolated area within a certain range.