The present disclosure provides a data accumulation device and method, and a digital signal processing device. The device comprises: an accumulation tree module for accumulating input data in the form of a binary tree structure and outputting accumulated result data; a register module including a plurality of groups of registers and used for registering intermediate data generated by the accumulation tree module during an accumulation process and the accumulated result data; and a control circuit for generating a data gating signal to control the accumulation tree module to filter the input data not required to be accumulated, and generating a flag signal to perform the following control: selecting a result obtained after adding one or more of intermediate data stored in the register to the accumulated result as output data, or directly selecting the accumulated result as output data. Thus, a plurality of groups of input data can be rapidly accumulated to a group of sums in a clock cycle. At the same time, the accumulation device can flexibly select to simultaneously accumulate some data of the plurality of input data by means of a control signal.