Abstract: To evaluate the adaptation of side guard plate at 37220-2 large dip angle thick coal seam fully mechanized caving face of Dongxia Coal Mine, by site observation, we got the side guard plate load characteristics. The monitoring results showed that the side guard plate is subjected to lateral force in generally, and side plate load is usually under 5 MPa, but when the lateral supports are adjusted, the pressure is higher instantaneously, and the load is up to 20 MPa to 25 MPa during periodic weighting. The monitoring analysis showed that the lateral force depends on the stability of support, there is larger lateral force when support is toppling or skidding and vice versa. The side plate of hydraulic support not only had an effect on preventing gangue leakage between adjacent hydraulic supports, but also more importantly adjusted support and prevented gliding and toppling in steeply dipping coal seam. Therefore, the side plate should be called "side adjusting plate", with the function of adjusting supports and preventing waste rocks, and more importantly play an important in adjusting supports. From the practical application and monitoring data of side plate, the overall strength of side plate is higher and the side plate using φ100 mm big cylinder bore side pushing jack can basically play role in adjusting support effectively in 37220-2 fully mechanized caving face.