The invention relates to a diverting agent effect evaluation true triaxial test machine which comprises a pressure loading system, a diverting agent injection system d a data collection control system. The pressure loading system comprises a pressure chamber, an oil pressure stabilizing source and a vertical loading device, a pressure chamber outer wall is arranged outside the pressure chamber, a rock sample and a flat jack are arranged inside the pressure chamber, the rock sample is provided with an artificial crack, the flat jack is arranged on a side face adjacent to the rock sample, the vertical loading device directly faces a top face of the rock sample, the vertical loading device and the flat jack are connected with the oil pressure stabilizing source, the diverting agent injection system comprises a constant-flux pump, a liquid injection container and a liquid incoming pipe, the constant-flux pump is connected with the liquid injection container which is connected with the artificial crack through the liquid incoming pipe, the data collection control system comprises a servo controller, a computer and a sensor, the sensor is arranged between the constant-flux pump and the liquid injection container and connected with the servo controller, and the oil pressure stabilizing source and the computer are connected with the servo controller respectively. By the diverting agent effect evaluation true triaxial test machine, optimization of diverting agent construction parameters in the process of fracturing can be realized effectively.