The invention discloses an annealing process of martensitic stainless steel cold-rolled strip steel for a tool, and belongs to the technical field of stainless steel machining. The problems that according to existing processes, strip breaking and oxidization are prone to occurring, oxide skins are uneven, the phenomena of oxidized residues, poor pickling, color difference and rough surfaces are prone to occurring, annealing raw materials pollute the environment and are high in cost, moreover, equipment is complex, the production line is long, and scratching is prone to occurring are solved. The annealing process comprises the following steps of raw material hot rolling, hot rolling annealing, hot line pickling, rolling, bell type annealing, and cutting and packaging. According to the annealing process, compared with common 2D production equipment, a bell type annealing furnace is simple in equipment, small in occupied area, low in equipment cost and easy to operate, a production methodis simple and easy to implement, manufactured strip steel is bright in surface, high in plasticity, toughness and quenching hardness, slitting machining, forming machining, surface machining and surface grinding are facilitated, and the tool with a small specification can be rolled and produced conveniently.