As an extension of traditional RTK algorithm, network RTK technology can provide positioning service performance with wider operation scope, lower cost, shorter initialization time and high precision by using atmospheric products of regional reference station network. First, the strategy of network RTK algorithm is summarized, and then the positioning performance of network RTK is evaluated and analyzed from three aspects: fixing effect of reference station ambiguity, modeling accuracy of atmospheric delay and positioning performance of terminal using measured data. The experimental results show that the horizontal positioning accuracy of network RTK technology and sing baseline RTK algorithm is better than 1 cm，the elevation positioning accuracy is about 2 cm，and the ambiguity fixation rate is close to 100%.