Abstract: Numerical simulation of transient flow is very important for the safe operation of long-distance water transmission pipelines in road utility tunnels. Recently, with the rapid development of polymer material technology, viscoelastic pipes, such as polyvinyl chloride（PVC） and polyethylene（PE）, have been widely used in road utility pipelines systems. Different from the mechanical characteristics of elastic pipeline, viscoelastic pipes have both elastic and viscous mechanical behaviors, which makes calibration of constitutive parameters particularly important in the numerical simulation of hydraulic transient process of viscoelastic pipes. Therefore, based on the transient flow model of viscoelastic pipe（using the Kelvin-Voigt model combined with the one-dimensional quasi-steady-state friction model）, this paper establishes a calibration model of viscoelastic pipe in urban road utility tunnels, and uses the Sequential Quadratic Programming（SQP） algorithm to solve it. Numerical results show that this calibration model is capable of identifying the constitutive parameters quickly and accurately at different water temperatures. It can provide theoretical support for the calibration of constitutive parameters in long-distance water transmission pipelines in road utility tunnels.