To meet the operation requirements of mobile manipulators with high precision and low-jitter， a novel vibration suppression method for trajectory planning based on the modified asymmetry combined sine function （MACSF） is proposed. Firstly， aiming at the problems of acceleration mutation and instability in the start-stop phase of the traditional asymmetry combined sine function （ACSF）， and taking the continuous smoothing of driving function and acceleration as the goal， the acceleration stage and deceleration stage in acceleration time window are designed by using improved combined sine function to reduce joint torque fluctuation of mobile manipulators. Secondly， the linear combination method is used to find the universal driving function satisfying the constraint conditions. Finally， an algorithm verification platform for mobile manipulators is built based on robot operating system （ROS）， and a series of experiments are carried out in prototype scenarios using this platform. The experimental results show that the MACSF method can effectively suppress the transient vibration and residual vibration of mobile manipulators， and the inhibition amplitude is within 1mm， which verifies the effectiveness and practicability of the method.