Due to the fact that the design depth of the preliminary design stage has not yet reached the standard of the construction drawing, the specific construction quantity, specifications and models and other information cannot be fully determined, and the preliminary design estimate often needs to learn from the experience of similar projects to calculate the cost. In order to ensure the accuracy and timeliness of cost calculation, this study sorted out the engineering quantity of process pipes in the industrial plant of the actual completed construction project, and obtained the calculation method of the number of relevant pipe fittings and the weight of supports, which is conducive to realizing the intelligent cost calculation of process pipe installation engineering cost, and provides a theoretical basis and calculation basis for further upgrading the relevant cost calculation software.