The invention discloses a dynamic high-temperature and high-pressure simulation evaluation instrument for a drilling fluid mud cake. The evaluation instrument is mainly composed of a kettle, a sample slurry cup, a thermocouple, a heater, a temperature control system, a pressure sensor, a pressurizing device, a stirring blade fixing device, a magnetic transmission device and a computer; the top of the kettle is provided with a kettle cover, the bottom of the kettle is connected with the magnetic transmission device, the upper portion of the kettle is provided with the stirring blade fixing device, the lower portion of the kettle is provided with a sample slurry cup tray, the sample slurry cup is placed on the tray, the thermocouple is arranged in the slurry cup, and the heater and the pressure sensor are arranged between the kettle and the slurry cup; the heater is connected with the temperature control system and the computer, the kettle is connected with the pressurizing device and a pressurizing/pressure relief valve, and the thermocouple, the pressure sensor and the pressurizing device are connected with the computer; drilling fluid is contained in the sample slurry cup, a blade shaft rod penetrates through an upper cover of the slurry cup to be connected with stirring blades arranged in the slurry cup and fix cores. The evaluation instrument can effectively simulate the process that the mud cake is formed by the drilling fluid on the well wall under the working conditions of a dynamic state, different temperatures, different pressures and the like and overcome the defects of the prior art.