The work aims to design a new parallel mechanism that can achieve complex motion in view of the status in the food industry, including large packaging workload, increasing labor cost and error-prone features. The spiral theory was used to analyze movement and constraint spirals of limb and the modified Kutzbach-Grübler formula was adopted to calculate the freedom of this mechanism. According to the relationship between mechanics and geometry, the relationship equation between the input parameters and output parameters of mechanism was built. Through the position relation equation, the relation equation of the velocity and acceleration about input and output of mechanism was obtained. Due to the complexity of the jacobian matrix, the problem of determining the matrix full rank was transformed into the problem finding the extremum of the multivariate function. According to the constraints of the mechanism, the working space of the motion platform about the mechanism was calculated. The fitness evaluation function of the positive solution of the mechanism was established and the positive position solution was solved by a method combining particle swarm optimization (pso) with iterative method. The trajectory planning of the center position about moving platform was carried out by the quintic polynomial, and the change rule of the kinematics input parameters was obtained. The results showed that this mechanism had one−translation and two−rotation degree of freedoms. By solving these mathematical models, it was found that the mechanism had no obvious singular configuration and the workspace was continuous and large. The high-precision positive position solution of the mechanism was obtained and the kinematics parameter of driving pair changed smoothly, conforming to the trajectory planning expectation. The new parallel mechanism can meet the requirement of large working space when food is grabbed and packed and realize smooth movement, and the results provide the theoretical basis for the dynamics analysis and real−time control of the mechanism.