A probe unit and a cell test method are disclosed. The probe unit comprises a movable unit which includes a first mark, an image acquisition unit which is configured to acquire an image including the actual relative positions of the first mark and a second mark on a display panel, a calculation unit which is configured to get the actual relative positions of the first mark and the second mark according to the image, a first position adjustment unit which is configured to move the movable unit to adjust the actual relative positions, and a first control unit which is configured to determine whether the first position adjustment unit adjusts the actual relative positions in place according to whether the difference between the actual relative positions and the theoretical relative positions of the first mark and the second mark under the condition of theoretically correct alignment exceeds a set value. The speed of detection can be increased. The work time can be reduced. The accuracy of alignment can be increased.