Catenary nanostructures enable continuous phase control. However, the ordinary catenary nanostructure has narrow width at both ends and is not easy to be fabricated. On the other side, it was difficult to build complex model directly in simulation software CST, and the simulation process was complicated in the past. The equal-width catenary slit is proposed to replace the normal catenary slit. And the equal-width catenary-type metasurface has been designed to generate Bessel beam, which provides a new idea for the design of two-dimensional optical de-vices. In the process of modeling and simulation, CST is combined with Matlab for co-simulation, and all operations, such as modeling, simulations, and parameter modification, are completed directly in Matlab. This method can be used to design complex structures, and more ideal simulation results can be obtained combined with the numerical optimization ability of Matlab.