The invention provides a multistage membrane-controlled continuous crystallization method, and belongs to the technical field of crystallization engineering. The method comprises the following steps:adding a solution to be crystallized into a crystallization tank, turning on a stirring and temperature-controlling device, and turning on a cooling or solvating-out material liquid loop; turning on asolution-to-be-crystallized loop after the system is stable to make the solution to be crystallized to respectively undergo crystallizing nucleation, crystal growth and crystal maturation in a multistage membrane assembly, carrying out cycle stabilization for a period of time, and conveying the obtained material to a filtering device and a drying device to obtain a final crystal product. The generation of crystal nuclei and the growth of crystals are systemically regulated through adjusting the flow amounts and the temperatures of the solution to be crystallized and the cooling or solvating-out material liquid and the contact time of two liquid phases in order to obtain the ideal crystal product.