Exhaust gas purification system control method and exhaust gas purification system

PROBLEM TO BE SOLVED: To stop a vehicle by a driver and perform a forced regeneration by a manual regeneration switch when it is detected that the detected collection amount is larger than a predetermined collection amount for determination regarding regeneration of a continuous regeneration type DPF device. In the exhaust gas purification system, the control method of the exhaust gas purification system and the exhaust gas purification system which can remarkably reduce the frequency of operation of the manual regeneration switch and improve the operability of the driver are provided. SOLUTION: In an exhaust gas purification system 1 provided with a continuous regeneration type DPF 13 and a DPF control means 30C, a predetermined first temperature rise determination for PM collection amount ΔPm is lower than a predetermined determination collection amount ΔP1. When the amount of trapping ΔP01 is exceeded, exhaust temperature increase control is performed by multi-injection. Thereafter, the amount of trapping ΔPm is for a predetermined second temperature rise determination lower than the predetermined amount of trapping ΔP01 for the first temperature increase determination. When it becomes less than the collection amount ΔP02, the exhaust gas temperature raising control by multi-injection is stopped. [Selection] Figure 4