The invention discloses a mechanical equipment fault diagnosis method based on deep learning. The method specifically comprises the following steps of S1, carrying out the data collection and preprocessing of a main data source and a secondary data source of mechanical equipment, and obtaining a data set; S2, a five-fold cross validation method being adopted to divide the data set into a trainingset, a validation set and a test set; and S3, establishing a fault diagnosis model based on the CNN and the BD-LSTM, inputting the training set into the fault diagnosis model, extracting hidden features, performing training, and outputting a diagnosis result. According to the method, BD-LSTM is adopted to perform smooth tracking and result prediction, and uncertainty caused by operation and environmental interference is processed, sensor monitoring data adopts CNN and BD-LSTM to extract hidden features in parallel, output of two irrelevant paths can influence prediction, and each parameter inthe network can be corrected according to predicted errors.