Wireless cellular communications lead to huge demands for estimating and visualizing the data about Quality of Service (QoS) for mobile network operators in the 5th Generation (5G) networks. Constructing a coverage map is an important step to visualize global information about QoS. Inspired by the characteristic of the base station, we present an adaptive triangulation method to divide the region of interest into triangles. Then, we propose a novel area-wise Multi-criteria Triangulation-induced Interpolation (MTI) algorithm which utilizes the linear interpolation to estimate the key performance indicators of the QoS inside a triangle with the known values of its three vertexes, to construct the coverage maps and provide the closedform solution of the covered region for the multi-criteria problems. We check the accuracy and the efficiency of the MTI algorithm both in 19-cells network scenario and in real big city scenario. The experiment results manifest that the MTI algorithm shows a good performance in constructing the coverage maps and it is significantly lower-cost and higher-efficiency than the traditional point-wise algorithms. INDEX TERMS Wireless cellular communication, coverage map, triangulation method, linear interpolation.