The properties of porous silicon(PS) and the application of the technology in solar cells were investigated,and the properties of PS solar cell and the effects caused by the instability of the cell were studied.It was confirmed by experiments that the application of photoluminescence(PL) and antireflection properties of PS in solar cell can enhance the efficiency effectively.The efficiency was increased by 83.89%,and the efficiency was 14.73%,but the effect of PS solar cell's instability on effieiency was obvious.