Refer to Fig.5 for practical application. The curve illustrated in Fig.5 uses FRC-2 type of apparatus with temperature rising velocity at 20摄氏度 /min. It will preserve the temperature for 10 minutes after the temperature reaches 700摄氏度from romm temperature; it will fall at 600摄氏度with temperature reduction velocity at 10 摄氏度/min and then it will rise and reaches the actual curve of 800摄氏度with the velocity at 30摄氏度 /min. The experiment sample is calcium oxalate. The curve indicates that the adoption of different self-setting PID parameters during temperature rising, preserving and reducing processes adapts to the control of temperature precision at different temperature rising and reducing velocities. Practical testing indicates that the overshooting number of system is ato=0.3% , which prove the effectiveness ofself-setting expert system PID parameters in the application of temperature control during thermal analysis instrument and acquires satisfactory control effects.