We systematically investigate the light absorption behavior of the Pb-based perovskite active layer in textured perovskite solar cells (PSCs) based on two-dimensional TiO2 nano-semisphere electron extraction layer by the finite element method (FEM). The simulation results reveal that enhanced light absorption efficiency of a 100-nm-thick textured perovskite layer achieves 64.8% under AM 1.5 G solar irradiation and owns increase of 16.8% in comparison to the control planar cell. To elucidate the origins of absorption enhancement, the detailed field distribution is investigated, displaying different photonic and plasmonic modes; their mutual coupling jointly resulting in a remarkable light absorption enhancement in the 600- to 800-nm-long wavelength range. Our textured PSCs offer an attractive solution to conserve Pb-based perovskite consumption and realize angle-insensitive and high-efficiency ultrathin PSCs.