Excessive use of carbendazim (CBZ) for controlling fungal disease may result in pesticide residues in growth environments. There is an urgent requirement for real-time detection of CBZ content to enable rapid assessment of pesticide residues. Herein, a novel electrochemical sensor was created, which utilizes a laser-induced graphene (LIG) electrode modified with two-dimensional (2D) tungsten disulfide (WS2) nanosheets and a poly(L-lysine) (PLL) film to construct a 2D-on-2D layered structure. The PLL/WS2/LIG electrode exhibits strong charge transfer, excellent electrocatalytic performance, and high CBZ adsorption capacity, thus leading to enhanced sensitivity. As a result, the sensor exhibits a low detection limit of 1.2 ng/mL (6.2 nM), high sensitivity up to 135.1 μA(μg/mL)−1cm−2, and a wide response range of 0.01 to 1.5 μg/mL. Moreover, an intelligent analysis system, consisting of a portable device that connects to an online cloud platform equipped with a machine learning model and visualization software, has been developed for the real-time detection of CBZ residues on tea leaves in tea plantations. This study demonstrates that the PLL/WS2/LIG sensor and the intelligent analysis system have great potential to monitor pesticide residues to guarantee food safety.