The invention provides a memory data sampling device which can accurately realize the purpose of sampling the output data of a memory chip to improve the reliability of the device. The memory data sampling device comprises a memory chip and a sampling controller, wherein the memory chip comprises an output data port and an output data sampling clock port; and the sampling controller comprises a first input unit, a second input unit and an asynchronous data buffer. A data writing end of the asynchronous data buffer receives clock signals to be used as an input writing clock, the sampling data is controlled to be stored in an internal memory, and after the sampling data is stored in the internal memory, a data reading port of the buffer is triggered to read the sampling data from the internal memory; an output data reading port can only be triggered under the condition that new sampling data is stored in the internal memory, thereby reading and outputting the sampling data; and the datasampling work of the memory chip can be accurately finished.