The invention provides a filter cake scraping system. The system involves a scraping device 1, a position adjusting device 2, a detecting device 3 and a control device 4; the scraping device 1 is usedfor scraping a filter cake; the position adjusting device 2 is connected with the scraping device 1, and is used for adjusting the position of the scraping device 1; the detecting device 3 is used for detecting the property of the filter cake to obtain a detection result; and the control device 4 is connected with the detecting device 3 and the position adjusting device 2, and is used for controlling the position adjusting device 2 according to the detection result provided by the detecting device 3. According to the system, the controllability of the scraping process is realized; based on the property of the filter cake, the position of the scraping device is adjusted, so that the direct impact on a filter screen in the material filtering process, the situation that fine-particle materials pass through the filter screen, and the times of contact between the scraping device and the filter screen are all reduced, and the damage on the scraping device and the filter screen is avoided; and the moisture percentage of a discharging layer is detected, the scraping device is adjusted to scrape the whole filter cake, so that the moisture percentage of the filter cake and the filtering efficiency are ensured to be in a stable state.