The effect of the temperature change on the friction of the spool valve pair is emphatically analyzed with the spool valve pair as a study object. The friction force generated by the spool valve pair was mainly composed of the friction force caused by the direct contact between the spool and valve sleeve and the friction force generated by the spool and the hydraulic oil. These two forces’ relationship with the temperature were analyzed respectively to deduce the theoretical calculation formula between the friction force generated by spool valve pair and the temperature. The analysis shows that the friction between the spool valve pair and the hydraulic oil decreases rapidly with the increase of temperature in the range of -50~50 ℃, and the friction force between the spool and the valve sleeve gradually declines with the temperature going up. In addition, the friction of the spool and hydraulic oil decreases slowly as temperature goes up in the range of 50~100 ℃, and its value is far less than the friction between the spool and the valve sleeve. Besides, the friction of spool valve pair declines with the temperature going up in the range of -50~150 ℃.