The present application provides a positive electrode sheet for a secondary battery, the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer on a surface of the positive electrode current collector, the positive electrode active material layer includes a positive electrode active material, the positive electrode active material includes a first lithium nickel transition metal oxide and a second lithium nickel transition metal oxide, the first lithium nickel transition metal oxide includes a first substrate and a first coating layer on a surface of the first substrate, the first substrate is secondary particles, and the second lithium nickel transition metal oxide is a single crystal or single-crystal-like morphological particles.