In this study, we use the swelling characteristics of bentonite to discussion about the performance of bentonite mortar anti-seepage and the performance of resistance to sulfate. And add the AE water-reducing to improve its workability. To compare with different rate of bentonite added at different ratio of AE water-reducing in the condition of Standard Test for Flow Table. We planning in different water-cement ratio (0.445,0.485,0.550) to test for its fresh properties and hardened properties, and discussion the effect by AE water-reducing on the marine engineering. According to this study, adding bentonite will make the flow value dropped, and affecting the workability. Because of the positive ion exchange properties between bentonite and water will make it a high volume exchange rate, it means that absorption is high, so when the mixing time, the bentonite will form clumps, in this study, we add the AE water-reducing to improve. After we add AE water-reducing, the absorption, compressive strength are increase, but we still had to pay attention to the ratio between bentonite and AE water-reducing, the strength of structure perhaps decrease if added too much bentonite. This study can get the best positive effect when added ratio of 0.25% of bentonite to replaced cement.