In order to solve the problems of low weeding rate and high seedling injury rate in the mechanical weeding operation of rice fields, an opticalmechanical composite weed control method was proposed to suppress weed photosynthesis by changing the turbidity of the water layer with the aim to control weed. By improving the traditional spiral propulsion device, a microspiral propulsion weed control machine suitable for paddy field soil environment was developed. The relationship curves between the drum speed and the working resistance and running speed of the spiral drum were established. The explicit dynamic analysis module LS-DYNA was used to simulate and analyze the working process of the weed control machine in the paddy field water environment to establish the spiral drum-soil-water coupling model. The fluid-solid coupling simulation was performed to solve, and the cutting resistance and power parameters of the weed control machine were collected in the operation condition. Through the test tank prototype test, the changing law of the influence of water layer thickness on water layer turbidity was explored. The results showed that the optimal speed of the designed microspiral propulsion weed suppressor machine was 400 r/min; the simulated resistance was 5.47% higher than the test value on average, and the simulated power was 6.06% larger than the test value on average. The simulation data was highly consistent with the performance test data, which verified the reliability of the simulation model. When the water layer depths in the test tank were 20, 40, and 60 mm, the duration of turbidity greater than 120 NTU were 5, 8, and 8 h, respectively.