Traditional carrier phase difference algorithm is not suitable for deformation monitoring, the accuracy of Real-Time Kinematic (RTK) positioning cannot meet requirements and static relative positioning based on carrier double-differential phase has poor deformation tracking performance with continuous calculations. To solve these problems, based on the deep research of dynamic and static algorithms, a dynamic and static adaptive fusion algorithm based on carrier phase difference was proposed. The convergence of positioning results was judged by variance-change method in real time, then the state priori estimation process of Extended Kalman Filter (EKF) was adaptively adjusted. In the process, the covariance value of priori estimation error of position parameters was increased at the convergence time, so that the posteriori process of EKF tended to trust measured value. EKF iteration was used at the non-convergence time, so that the posteriori process of EKF tended to trust state predicted value. The experimental results show that compared with traditional RTK, the accuracy of the new algorithm is improved, with horizontal accuracy of ±2 mm, and altitudinal accuracy of ±4 mm. Compared with static positioning, the observation period is reduced, and the tracking performance of micro-deformation is improved.