To study the erosion situation of the control valve in the oil slurry system of the FCC unit, the ratio of the control valve flow rate to the valve position is defined as the erosion coefficient. This coefficient is used to characterize the degree of erosion of the regulating valve. The impact of the solid content of the oil slurry and the differential pressure between the oil slurry pump and the regulating valve on the degree of erosion of the regulating valve is quantified through the erosion coefficient. Comparing FCC units with different process flows for A and B oil slurry systems, it is found that there are significant differences in the tolerance of the two units to the solid content of the oil slurry. The outlet pressure of the oil slurry circulation pump in Unit A is 1.4 MPa, and the pressure difference between the slurry pump and the regulating valve is about 0.5 MPa. The regulating valve is severely eroded. The outlet pressure of the oil slurry circulation pump of Unit B is 0.4 MPa, and the variable frequency method is used to adjust the oil slurry circulation volume to meet the demand for slurry circulation volume. The unit has been operating safely for up to 8 months under high solid content conditions, and the regulating valve has not experienced significant erosion. Therefore, reducing the pressure of the oil slurry system is an effective means to reduce the risk of erosion and leakage in the oil slurry system.