Six-axis accelerometer is a kind of inertial sensors getting kinetic parameters in the field of aerospace, robots and the like, and researches on it at home and abroad are still at exploring stage. A new scheme of using parallel mechanism as plastic structure and piezoelectric ceramic as sensitive element of the transducer is presented. Piezoelectric ceramic is also used to serve as prismatic pair of parallel mechanism and traditional spherical pair is replaced by flexure spherical hinge. Three coordinates are consolidated at mass-block, shell and ground respectively, and their relationships of position and pose are established according to the theory of multi-body system. Based on Newton-Euler method, the dynamic equation of the system is established, and the problem is transformed into two initial value problems of first-order ordinary differential equations, which are solved by improved Euler method, by introducing aided angular velocity and using quaternions to describe rotation matrix and angular velocity, and accelerations are decoupled. Method of generalized inverse for matrix is used to treat the violated constraint problem of quaternion. Based on the established mathematical model, a numerical example is computed. The result is contrasted with the simulation result in ADAMS, and the relative error between them is acceptable. Meanwhile, time of data processing is no more than that of sampling. At last, the experiment is done, which shows that the new sensor can be used to measure six-axis acceleration real-timely and accurately.