Logistics cluster is an important form of reducing cost and increasing efficiency of logistics industry, and Horizontal Logistics Collaboration (HLC) is the essence. But it is affected by many constraints. The article constructs a model of “HLC constraints”composed of “collaborative environment”, “partner”,“trust”and“information system”, and builds a story line illustrating the logical relationship between them on base of semi-structured in-depth interviews with managers of seven large logistics clusters in Western China, enterprise representatives, government officials, experts and scholars, and coding analysis of Grounded Theory. And the three “model of function mechanism” reveals the internal relationship and interaction of constraints in the planning, implementation and evaluation stages. On this basis, corresponding countermeasures and suggestions are put forward in order to eliminate resistance, promote collaboration and development of logistics cluster, the transformation and upgrading of logistics industry in Western China.