The invention discloses a non-invasive load decomposition method and system. According to the scheme, the method comprises the steps of acquiring a load total power sequence of a target user within aperiod of time; and based on the load total power sequence of the user and set load types, decomposing load total power to obtain power characteristic sequences of the load types in the time period according to pre-trained relations between the total power sequence and the power characteristic sequences of the load types, wherein the load types are determined by using conditions of household appliances by the user. The training process comprises the steps of performing receptive field amplification based on identity mapping and a time sequence. The non-invasive load is decomposed through the pre-trained relations between the total power sequence and the power characteristic sequences of the load types, so that the correctness and accuracy of a load decomposition result are improved; and inthe training process, the load total power is subjected to a receptive field method according to the time sequence through the identity mapping, so that the problem of gradient disappearance in the load decomposition process is solved, the receptive field is expanded, and the load decomposition result is more authentic.