Provided is a biological sample imaging device and a biological sample imaging method that are capable of disposing a sufficient number of large-sized particles in a biological sample so as to be moderately dispersed within an imaging range. The biological sample imaging method includes: a first step of introducing a biological sample (104) containing particles into a liquid flow channel (40); a second step of causing the biological sample (104) introduced into the liquid flow channel (40) to flow in a forward direction; a third step of causing the biological sample (104) to flow in a reverse direction after the second step; and an imaging step of taking, in an imaging cell (14), images of the particles contained in the biological sample (104) that remains in the liquid flow channel (40) after the third step.