The additional task allocation model of equipment maintenance can not realize the dynamic comprehensive balance of maintenance task and maintenance personnel. So on the basis of determining the influencing factors of maintenance task allocation, a dynamic allocation model was proposed to solve this problem in this paper. To realize the numerical operation and analysis of this allocation model, the interval numbers was used to quantified express the fuzzy and uncertain characteristic parameters such as task importance, skill level and ect.. In addition, the calculation method of adaptation degree parameters and model were also given. The simulation results show that the model has better effect to balance the candidate load and task successful rate.