The invention belongs to the technical field of polymeric surfactants and discloses an environment-friendly block polyether emulsifier for a through hole material, a preparation method of the environment-friendly block polyether emulsifier and application of the environment-friendly block polyether emulsifier as a high-performance assistant in the fields such as ceramic. The emulsifier is at least one of etherification terminated or C4-C18 long-chain alkyl esterification terminated or esterification and etherification mixed terminated linear block polyether PEO-PPO, PEO-PPO-PEO, PPO-PEO-PPO and PEO-PBO-PEO which contain PEO chain segments. The invention further provides the preparation method of the emulsifier. According to the emulsifier, the temperature sensitivity of original polyether is reserved, in a free radical polymerization system, along with heat release of a polymerization reaction, the temperature is increased, water contained in terminated polyether is changed to be beneficial for mutual communication, and the mutually communicated through hole material (or open-cell material) is formed. Excellent through hole forming performance is achieved, and the emulsifier is good in emulsifying performance, safe and environmentally friendly, and can be applied as the high-performance assistant in the field such as the ceramic.