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 containing particles into a liquid flow channel; a second step of causing the biological sample introduced into the liquid flow channel to flow in a forward direction; a third step of causing the biological sample to flow in a reverse direction after the second step; and an imaging step of taking, in an imaging cell, images of the particles contained in the biological sample that remains in the liquid flow channel after the third step.