The invention relates to load parameter measuring technology of deep soil layers, and discloses a high-pressure, waterproof and self-stabilized type load testing device for the deep soil layer. The device comprises a driving system, a data recording instrument, a load cell and a concrete self-stabilizing block; the data recording instrument and the driving system are connected with the load cell through pipelines and used for acquiring the load data and driving the load cell to run, wherein the load cell comprises a bearing plate, a cell body, a hydraulic mechanism and a sensor; the bearing plate is connected with the hydraulic mechanism and driven by the hydraulic system to linearly move so as to transmit pressure to the soil layer; the hydraulic mechanism is sealed into the cell body, and the cell body is formed into the concrete self-stabilizing block by pouring; the sensor is connected with the data recording instrument and used for transmitting load data; the concrete self-stabilizing block is used for keeping the load cell stable and balanced, preventing the load cell from being inclined, and sealing the load cell; the load cell and the concrete self-stabilizing block are of a symmetric structure and are symmetrically overlapped relative to a shaft. With the adoption of the device, the load parameters of the soil layer can be tested.