The estimation of resource level’s envelope is a basic problem in constructing a feasible schedule for resource utilization. A new resource reasoning description method that combining resource temporal network, constraint network and temporal network was proposed by analyzing the resource constraint characteristics, such as coexistence of sharing and detaching resource, coexistence of cumulative and instantaneous consumption, coexistence of over-subscription and interval scheduling resource. Considering the specific characteristic of resource temporal network, a resource model was constructed, and two algorithms of the EBA (Envelop Based Algorithm) based on maximal flow and the ESTA^c (Early Start Time Algorithm with Chaining) based on early start time solution to solve with a resource feasible solution were given. The incremental EBA algorithm and ESTA^c algorithm were presented to get a feasible solution quickly. Finally, some experiments were presented to prove the validity of the methods. Results show that the efficiency and validity of the proposed methods are better than EBA algorithm and ESTA^c algorithm in solving the problems of resource constraint reasoning.