Aimed at solving the difficulties of multi-connected split air conditioning system in bills of quantities and valuation, based on current GB50500-2013 "Code of bills of quantities and valuation for construction works" and GB50856-2013 "Standard method of measurement for general building services works", by using the method of case analysis, the items of bills of quantities were listed such as indoor and outdoor air conditioner, copper pipe and flow distributor, refrigerant charge, system debugging. Sichuan and Guangdong Province quota were respectively applied to calculate the price of each item, and the calculate result of the different categories were analyzed, the ideas and methods to solve the difficult points were provided.