The work aims to solve the offline detection, small sizing amount, difficult detection and low efficiency in current test method of cigarette paper overlap sizing amount. Two online detection methods for lap adhesive sizing amount were designed, namely the laser sensor method and the external clamp ultrasonic flowmeter method. Both methods calculated the sizing amount per product by measuring the total mass of glue consumed and the total number of products produced within a certain period of time. Among them, the laser sensor method mainly measured the number of rotations of the pulley and calculate the total sizing amount based on the mass of adhesive output per rotation of the pulley; The external clamp ultrasonic flowmeter method mainly measured the cumulative flow of adhesive in the adhesive pipe and then calculated the sizing amount. To verify the feasibility of the two methods, the traditional glue gun adhesive output method, the laser sensor method, and the ultrasonic flowmeter method were used to measure the lap adhesive sizing amount of 1.0, 1.5, and 2.0 mg per cigarette. The detection results showed that under different lap adhesive sizing amount, the maximum relative error of the laser sensor method was smaller than that of the external clamp ultrasonic flowmeter method. Both the laser sensor method and the ultrasonic flowmeter method meet the online detection requirements for the lap adhesive sizing amount of 1.0 to 2.0 mg per cigarette. The laser sensor method has higher measurement accuracy, while the external clamp ultrasonic flowmeter method is more convenient for installation and use.