Disclosed are an acetylsalicylic acid derivative, i.e. a 2-(diethylamino)ethyl 2-acetoxy-benzoate hydrochloride crystal, and a preparation method and use thereof. The X-ray powder diffraction (XRPD) pattern of the crystal has characteristic peaks at the following 2¸ angle: 11.0° ± 0.2°, 20.6° ± 0.2°, 25.1° ± 0.2°, 8.2° ± 0.2°, 16.5° ± 0.2°, 13.4° ± 0.2°, 25.4° ±0.2°.