This paper proposes a novel rotating interferometer-based algorithm for parameter estimation of nearfield source. The algorithm exploits the rotation of a single long baseline interferometer and the integration operation of the phase to unwrap the phase ambiguity. Thus the contradiction between the maximal unambiguous angle and the direction finding accuracy in the single baseline interferometer can be efficiently eliminated in the near-field source scenario. The algorithm can obtain the closed form solutions of the elevation and azimuth angles as well as range estimations for near-field source with two receiving sensors. It avoids the construction of high-order cumulant matrices and multi-dimension search. Simultaneously, it alleviates the requirment for multi-baseline channel consistency. Compared with the conventional double long baselines interferometer method, the proposed algorithm achieves higher parameter estimation accuracy and better performance in ambiguity resolution. Moreover, the proposed algorithm enjoys a simple structure, which is easy to be implemented in engineering application. Simulation results demonstrate the effectiveness and validity of the proposed algorithm.