Rice mulching and transplanting technology is a great innovation in organic rice cultivation. It has many advantages such as temperature-increasing, water-holding, fertilizer-maintaining, improving physical and chemical properties, raising fertility, reducing weed growth, alleviating disease, increasing yield and so on. There are many researches about paddy weeding machine around the world, however, there is no mature weeding machine for mulching rice in paddy field. A new type of 3SCJ-1weeding machine was designed by using new weeding components for transplanting rice of organic rice. The motor power of the machine was provided by a two-stroke engine, which consisted frame, power transmission system, floater and compound weeding components, including walking wheel and weeding device. It achieved pulling and bury-pressing on weeds through the rotation of weeding device, kinematics and dynamics analysis of the weeding device were carried out at the same time. In June 2017, experiments were conducted in Wuchang by taking the forward speed and weeding depth as variables, and taking weeding rate as index. The results showed that when the forward speed was increased from 0.3m/s to 0.6m/s, the weeding rate was increased first and then decreased, and the weeding rate reached the maximun, which was 78.52% at the forward speed of 0.45m/s;when the weeding depth was ranged from 50mm to 110mm, the weeding rate was increased continuously, however, considering the power consumption of weeding machine, the best weeding depth was 50~100mm，and the weeding rate reached 79.26% at the weeding depth of 100mm, the average weeding rate of the weeding machine was 78.02%, which could satisfy the weeding agronomic requirements of mulching paddy field.