Missile-borne bistatic forward-looking synthetic aperture radar (MBFL-SAR) can achieve full-range, forward-looking, two-dimensional high-resolution imaging during the diving phase, enabling collaborative combat between missiles and improving guidance accuracy. In response to the issue that the trajectory of the transmitter directly affects the resolution of bistatic imaging, the two-dimensional resolution characteristics of the diving phase in the MBFL-SAR are analyzed. Combined with the motion characteristics of the missile, under the constraints of two-dimensional resolution and missile kinematics, the three-dimensional acceleration variations of the missile are used as optimization variables, and an objective function related to the angle between the resolutions in the scene is constructed.An improved genetic algorithm is employed for the trajectory optimization of the transmitter. Compared with the existing trajectory design method based on a linear attenuation model, the trajectory optimization method proposed in this paper can better meet the requirements of high-resolution imaging.