The utility model provides a post -cast strip preprocessing device, including setting up stagnant water steel sheet and at least one slip casting pipe unit on the post -cast strip, slip casting pipe unit include the level pipe and with an at least vertical pipe of level pipe intercommunication, the level pipe is located the below of stagnant water steel sheet, be provided with a plurality of out grouting holes units on the level pipe. The utility model provides a post -cast strip preprocessing device, it can carry out the shutoff tightness to the post -cast strip under the condition of not haring the post -cast strip reinforcing bar, and it is more convenient to be under construction.