Permeable protective siloxane paste was prepared by the method of outside emulsification with the use of external self long carbon chain alkyl silane as raw materials. First, the emulsification process were studied and the results show that while the mass ratio of Gransurf 61 and Gransurf 71 is 1∶1, the addition(by mass) of emulsifier is 4%, the particle size of the prepared paste is evenly distributed, the evaporation rate is the lowest, and the stability is the best, which can be saved more than 10d and 60d under 50℃ and at room temperature, respectively. Water contact angle, water absorption, penetration depth and overall coating performance of the concrete protected by the prepared paste were tested. The results show that when the carbon chain length of the siloxane becomes longer and longer, the depth of penetration of the paste prepared becomes smaller and smaller, the contact angle of water on protective surface becomes larger and larger; water contact angle of concrete surface protected by the prepared paste is greater than 1297°, the reduction of water absorption is greater than 9153%, the penetration depth is larger than 30mm, which meets the requirements set forth in the technological standard. The comprehensive protection performance of complex paste is better than that of single type, especially, the comprehensive performance of product C10+C14 is the best. When the number of the coating times increase, the protective effect of concrete are further improved, even a superhydrophobic concrete surface can be obtained.