The invention discloses a method for monitoring livestock breeding living body weight based on the internet of things. The method comprises: a camera and a sensor collecting data, when data collectionis completed, transmitting the data to a single board computer, the single board computer integrating the data, and transmitting the integrated data to a C / S terminal of a local terminal to perform next-step processing; on the local terminal C / S, firstly performing living body identification on acquired RGB images, combined with depth point cloud data of a depth camera, deducing a 3D point cloudimage, meanwhile uploading RGB and 3D point cloud images, and individual information of living bodies and environment variable collected by the sensor to a cloud server; the cloud server cleaning anddenoising the 3D point cloud images according to the uploaded individual information and environment variable, after the 3D point cloud images reach a standard, restoring volume to obtain living bodyvolume, and calculating mass; returning an obtained living body mass result to the C / S terminal, if objection for error of mass exists, correcting errors by hand, after error correction, recording anduploading to the cloud server.