Abstract: In order to realize automatic cutting with high precision and autonomous cruising of tunneling equipments, a analysis method of automatic cutting section boundary control error for longitudinal roadheader was proposed. The error sources of automatic cutting control system for roadheader had been made clear, which were mainly from steady-state error of control system, sensor precision, inertia of cutting arm, system control method and other non-theoretical calculation factors. The system was simulated and the results showed that influence of load disturbance on system steady-state characteristics was low and the system was stable. Each error was calculated and the maximum error of automatic cutting section boundary control was 71.30 mm in horizontal and 55.27 mm in vertical, which showed that the system fully met the highest standard of Standard for Quality Inspection and Assessment of Shaft Sinking and Drifting of Coal Mine. Through ground tests of automatic cutting control for roadheader, the maximum error of section boundary control was 45 mm in horizontal and 12 mm in vertical in actual measurement.