Traditional radar Doppler jamming signal generation based on DRFM is proven to be an effective method, which cheats radars by the method of storing radars signal in digital domain, and generating Doppler frequency shift through modulating. On the other hand, radar jamming signal generation based on photonic radio frequency storage is able to reserve radar signals fingerprint information, but is not able to generate desired Doppler modulation. This article suggests a technology of radar Doppler jamming signal generation based on microwave photonics time-stretch effect. Taking advantage of photonic radio frequency storage, through the effect of microwave photonics time-stretch, it added a certain Doppler frequency shift to the radar signal modulated into the optical domain, in order to cheat radars in velocity. Simulation was conducted to prove this methods feasibility and its effect.