This paper mainly introduces the development of space gravitational wave transmission and laser propagation in space gravitational wave detection. We profile the calculation methods used in the simulation of laser propagation and jitter noise in space-based laser interferometry. Compared with ground detection, space gravitational wave detection can effectively reduce noise and increase the length of the interference arm to realize high-precision gravitational wave detection. Under the distance of millions of kilometers and the precision requirements of the picometer level, it is necessary to consider the phase noise caused by pointing jitter with the telescope. Research has shown that defocus and astigmatism are the main aberrations affecting jitter noise at a distance of 2.5×10⁹ m. There is a deviation between the phase stationary point and the origin position. To minimize the phase noise, the telescope angle needs to be adjusted. The gravitational wave detection at the phase stationary point can effectively reduce the phase noise and the requirements of the telescope exit pupil wavefront RMS. The large defocus and small coma can make the phase stationary point close to the optical axis and increase the received laser power.