A positive electrode plate, a secondary battery, a battery module, a battery pack, and an electrical device are disclosed. The positive electrode plate includes a positive current collector, and a positive active material layer disposed on at least one surface of the positive current collector. The positive active material layer includes a first active material layer and a second active material layer that are sequentially stacked in a direction away from the surface. The first active material layer includes a first composite particle. The first composite particle includes a first lithium iron phosphate particle and a first carbon layer that coats a surface of the first lithium iron phosphate particle. The second active material layer includes a second composite particle. The second composite particle includes a second lithium iron phosphate particle and a second carbon layer that coats a surface of the second lithium iron phosphate particle.