The invention discloses an oil-well cement temperature-sensitive slow-release coagulation accelerator. The oil-well cement temperature-sensitive slow-release coagulation accelerator is prepared by employing an oil phase separation microcapsule technology. The method comprises the following steps: adding 3-5 weight parts of stearic acid and 100-125 weight parts of an organic solvent in a triangular flask, fully stirring the materials, heating water-bath at the temperature of 70-80 DEG C until stearic acid is fully dissolved, then adding 1-3 weight part of polyethylene glycol 4000 and 1-2 weight parts of a coagulating material, stopping stirring after 1-3 min, performing ultrasonic vibrating for 10-20 min, uniformly dispersing polyethylene glycol 4000 and the coagulating material in a solution, re-stirring the materials, and gradually cooling the material to the temperature of lower than 35 DEG C, filtering the material, and performing normal temperature drying on the material for 24 h to obtain the product. The oil-well cement temperature-sensitive slow-release coagulation accelerator has stable performance in a cement mortar, can be slowly released after reaching a preset temperature spot, has good slow releasing effect, the coagulation accelerator can obviously shorten the curing time of deep well and extradeep well after release, effectively solve the super-retarding problem of the deep well and the extradeep well, the preparation method is simple, the raw materials are common, the cost is low, the accelerator is easily popularized, and has wide market prospect.