The invention relates to a detector for electric fire prevention, in particular to a separated type detector for electric fire prevention. The separated type detector provided by the invention comprises a substrate with a mounting base for mounting a residual current transformer, the residual current transformer, a residual current transformer sealing cover and an intelligent module, wherein the residual current transformer is mounted in the substrate; the residual current transformer sealing cover is used for fully sealing the residual current transformer; the intelligent module is connectedto the substrate with the mounting base for mounting the residual current transformer after being inserted into a small box for containing the intelligent module in the residual current transformer sealing cover; and overlapped parts are squares with the same size. In such a way, the detector provided by the invention can be conveniently assembled and disassembled according to different onsite conditions, and the cost is solved.