Using environment-friendly cutting fluid in the process of metal cutting is one of the valid paths to carry out the green manufacturing. Using metacrylic acid ester, castor oil and boride as the main raw materials, a new type of environment-friendly water-base cutting fluid had been obtained. The main components of this cutting fluid are some kind of high molecular polymer and some kind of B-containing castor oil EP agents. The test results show that the cutting fluid has good stability, antirust property and biodegradability. The maximal non-chucking load value (PB) of the cutting fluid, whose consistency is 5%, can be 1068N. In the comparison with dry cutting, cutting force using environment-friendly cutting fluid is reduced by 23% in a certain condition. Using this cutting fluid can raise stock-removing efficiency and cutting quality, and extend the service life of cutting-tool. And this cutting fluid is harmless to operators and free from pollution to the environment. Expansion and application of the environment-friendly cutting fluid are advantageous to promote the development of the green manufacturing.