The utility model discloses a 3D printing powder scraping device with a collision detection function, which comprises a driving part and a scraper driven by the driving part, and a transmission part is further arranged between the driving part and the scraper; the transmission piece is connected with the driving piece through a first spring to form a first telescopic part, and the transmission piece is connected with the scraper through a second spring to form a second telescopic part; the first telescopic part further comprises a first limiting structure used for limiting the telescopic length of the first spring. The second telescopic part further comprises a second limiting structure used for limiting the telescopic length of the second spring. A first displacement sensor used for detecting the distance between the driving piece and the transmission piece is arranged on the driving piece, and a second displacement sensor used for detecting the distance between the scraper and the transmission piece is arranged on the scraper. According to the utility model, the displacement sensor is used for detecting the displacement change of the transmission spring caused by stress stretching. And the displacement sensor detects the displacement of the transmission spring to monitor the collision of the scraper. Low cost and high reliability.