The present invention provides a method for low-temperature and low-pressure synthesis of a halite crude oil hydrocarbon inclusion crystal. The method comprises carrying out gradual cooling crystallization on a supersaturated halite and crude oil hydrocarbon mixing solution under a normal pressure, and specifically comprises: 1) preparing a supersaturated halite solution, and cooling under a normal pressure to prepare a halite seed crystal; 2) placing the halite seed crystal prepared in the step 1) into a container, and adding the supersaturated halite solution to the container; 3) adding crude oil hydrocarbon to the supersaturated halite solution added with the seed crystal to form an oil-water mixing solution; and 4) carrying out cooling crystallization to obtain the crystal.