To research the friction performance of grease lubricated sliding bearing of the boom in engineering machinery under long-time action of cyclic radial heavy load, a friction torque and coefficient test bench for this kind of bearing has been developed. The test bench can not only simulate the working process of the bearing under the condition of low speed and heavy load approximately, but realize two relative movement forms between bearing and pin shaft. Based on the bench, experiments about the relationship between active torque and friction torque on the sliding bearings in the working process are carried out, and a test calculation method of the friction torque and coefficient is introduced. The wear test shows that the method can be used to accurately obtain the friction coefficient between the bearing and pin shaft. The method provides references for designers to estimate the bearing life and work efficiency, as well as for the optimal design of this type of bearing.