A treatment method for laterite nickel ore by curing and roasting-water leaching-atmospheric pressure acid leaching falls within the technical field of metal smelting. The treatment method includes the following steps: mixing a laterite nickel ore dry powder, concentrated sulfuric acid, and sodium fluoride uniformly, and then performing curing and roasting under a reducing atmosphere to obtain a cured material; performing water leaching on the cured material to obtain a water leaching solution and a water leaching slag after filtration; performing atmospheric pressure acid leaching on the water leaching slag to obtain an acid leaching solution and an acid leaching slag after filtration. In the treatment method of the present invention, the reaction is controllable, the reaction period is short, the reaction energy consumption is low, and the production cost is low; compared with the traditional high-pressure acid leaching process, it can significantly reduce acid consumption, reduce the loss of valuable metals such as cobalt and nickel, improve metal yield, and increase the economic benefits of production. The treatment method of the present invention can effectively ensure the leaching rate of cobalt and nickel, at the same time, reduce the corrosion of equipment by strong oxidants, reduce the discharge of waste liquid in the leaching process, and reduce the production cost.