The invention relates to a preparation device and method of forming a ceramic coating on a sintered type NdFeB permanent magnet (8). The preparation device comprises a holding barrel (1), a pump body (2), a spraying system, and a fixture mechanism. The pump body (2) is connected with the holding barrel (1) and the spraying system, and the spraying system is located above the fixture mechanism and there is a distance between the spraying system and the fixture mechanism. The fixture mechanism is connected with a recovery bucket (7) through a pipeline (6), and the recovery bucket (7) is connected with the holding barrel (1) through a pipeline. The spraying system comprises a nozzle (5), wherein the inlet of the nozzle (5) is connected with a pipeline (3) of the pump body (2). The fixture mechanism comprises a support plate (11), an upper recovery trough plate (9) and a lower recovery trough plate (10), wherein the lower recovery trough plate (10) is located above the support plate (11). The lower recovery trough plate (10) is symmetrically arranged on both ends of the upper recovery trough plate (9). The outlet of the nozzle (5) is located above a containment space of the spraying system.