Using the structure search of particle swarm optimization (PSO) algorithm combined with density functional theory(DFT),we conduct a systematic two-dimensional (2D) material research on the SiO and discover a P2 monolayer structure.The phonon spectrum shows that the 2D P2 is dynamic-stable under ambient pressure.Molecular dynamics simulations show that 2D P2 can still exist stably at a high temperature of 1000 K,indicating that 2D P2 has application potential in high-temperature environments.The intrinsic 2D P2 structure has a quasi-direct band gap of 3.2 eV.The 2D P2 structure can be transformed into a direct band gap semiconductor by appropriate strain,and the band gap can be adjusted to the ideal band gap of 1.2 eV-1.6 eV for photovoltaic materials.These unique properties of the 2D P2 structure make it expected to have potential applications in nanomechanics and nanoelectronics.