The disclosure relates to a light blocking sheet and a lens module. The light blocking sheet includes an inner hole. A plurality of micro concave structures are regularly disposed on a periphery of the inner hole. The micro concave structure extends from the periphery of the inner hole to a direction far away from a center of the inner hole. A depth of the micro concave structure is d, an outer ring diameter of the light blocking sheet is D1, d and D1 meet 0.01≤d/D1≤0.05. According to the light blocking sheet of the disclosure, the micro concave structures are disposed on the periphery of the inner hole, so that stray light may be effectively suppressed.