Abstract: Construction machinery industry product replacement very fast, customers not only require products strong and durable, but also need a good appearance. The important mounting seat of bulldozer products（such as engine, gearbox and cab, etc.） depends on the finishing of large-scale equipment. The conventional positioning fixture adopts thick plate welding, machining and assembly, and the pin shaft positioning has high accuracy, but the manufacturing cycle is long, the cost is high, the weight is big, and the frequent movement causes the labor intensity to be big. Our company gradually popularized the application of the space template in the production practice, not only meets the assembly production requirements, but also the manufacturing cycle is short, convenient and practical,improves the assembly welding accuracy, avoids assembly interference frequent repair, adapt to the pace of product replacement.