The invention relates to a P-type single crystal silicon battery and a manufacturing method thereof, The manufacturing method comprises the steps of forming a plurality of corresponding first strip grooves and a second strip grooves arranged in parallel on the upper and lower surfaces of the P-type single crystal silicon wafer, wherein the ratio of the depth of the first strip grooves to the thickness of the P-type single crystal silicon wafer is 0.6-0.8, and the ratio of the depth of the second strip trench to the thickness of the P-type single crystal silicon wafer is 0.5- 0.7, and the thickness of the monocrystalline silicon layer between the first strip-shaped trench and the adjacent second strip-shaped trench is 25- 35 micron; Then forming an N-type phosphorus diffusion layer, an N-type heavily doped phosphorus diffusion region and a P-type heavily doped boron diffusion region; Then, a passivation layer and an electrode are respectively formed on the upper and lower surfaces of the P-type single crystal silicon wafer. The P-type monocrystalline silicon battery of the present invention has excellent photoelectric conversion efficiency.