The utility model discloses a dynamic balance analysis device. A vibration signal caused by imbalanced rotation of an external input motor is sent into an FIFO (first in first out) connected with the motor after being processed by a front-end signal processing unit; an FFT (fast fourier transform) processor is connected with the FIFO, processed intermediate data and original data are stored in a double-port RAM (random-access memory) unit connected therewith; a data processing unit is connected with the double-port RAM unit to obtain and send quality and relative position of output compensation through calculation to a display unit connected with the double-port RAM unit for displaying; and a control unit is connected with the front-end signal processing unit, the FFT processor, the double-port RAM unit and the data processing unit respectively and used for reading and writing addresses, enabling signals and controlling the starting of related modules. The device greatly improves system resolution and analysis speed of the system by adopting FFT real-time analysis technology, and is applicable to wide popularization in application situations such as dynamic balance detection, vibration analysis, compensation and the like.