In order to reduce the influence of fast moving jamming signal and desired signal steering vector mismatch on radar performance, a robust joint transmit-receive beampattern design method for MIMO radar under jamming environment is proposed in this paper. At the transmitter, the derivative constraint method is used to constrain the eigenvector of the jamming signal, and the transmit beampattern is designed by establishing the optimization model to minimize the peak sidelobe level. At the receiver, the diagonal loading technique is applied to reduce the effect of the desired signal steering vector mismatch on the beamformer performance, and the optimal loading value can be determined by establishing the optimization model to minimize the difference between the output signal-to-interference-plus-noise ratio and the optimal signal-to-interference-plus-noise ratio. By designing the joint transmit-receive beampattern of MIMO radar, not only the jamming signal can be effectively suppressed, but also the desired signal cancellation phenomenon can be avoided, so as to improve the performance of MIMO radar. Experiment results demonstrate the validity of the proposed method.