Positive electrode precursor and continuous preparation method thereof, positive electrode material and secondary battery

The invention belongs to the technical field of battery materials, and particularly relates to a positive electrode precursor, a continuous preparation method of the positive electrode precursor, a positive electrode material and a secondary battery. The continuous preparation method of the positive electrode precursor material comprises the following steps: preparing a mixed salt solution of nickel salt, cobalt salt and manganese salt; adding the mixed salt solution, the alkali liquor and a complexing agent into a reaction kettle for reaction, and monitoring the particle size of materials in the reaction kettle in real time; when the particle size D50 of the material in the reaction kettle reaches 75-85% of the target particle size D50, starting a concentration circulation system to control the solid content of the slurry; and when the particle size D50 of the material in the reaction kettle reaches the target particle size D50, collecting the qualified material, and purifying to obtain the positive electrod