Deep space exploration has great significance for human being to develop and utilize space resources. Remote sensing payload is a very important part of deep exploration. Since the detection distance in the deep space exploration mission is very far, the SNR of the received signals is very low, the capture of extremely weak signals from deep space is a key technology. Based on the requirement of future deep space exploration for ultra weak signal detection, a week signal detection method was given. The method was based on quantum squeezed states, whose shot-noise was less than the standard quantum limit, and some experimental results were given. The result shows that this technique was a promising technology in future deep space exploration. Because the quantum properties of squeezed light is attenuated as the distance increases, in order to be closer to the application, a new laser radar scheme was designed which injected squeezed light at the receiving end, and simulation results were given.