The invention discloses a grinder for a food processor. The grinder comprises a container body which is a rotating member. The container body is internally provided with a grinding chamber. The container body is provided with a top wall and a side peripheral wall. The grinding chamber is provided with a first material opening and a second material opening. One in the first material opening and the second material opening is a material inlet opening, and the other one is a material outlet opening. The bottom surface of the container body is open for forming the first material opening. The second material opening is formed on the side peripheral wall or the top wall or extends from the side peripheral wall to the top wall. In use of the grinder for the food processor according to the embodiment of the invention, a food material can be fed through the material inlet in the first material opening and the second material opening; after the food material is crushed in the grinding chamber, the crushed food material is discharged out of the material outlet opening; and a grinding process is finished in the grinding chamber. The grinder for the food processor further has advantages of small operation noise, high pulp preparation efficiency, high pulp preparation effect, high concentration of the prepared pulp, and low energy consumption.