The invention belongs to the field of metal processing fluids and discloses an environment-friendly semisynthetic cutting fluid for titanium alloys as well as a preparation method and an application of the cutting fluid. The cutting fluid comprises components in percentage by mass as follows: 20%-30% of base oil, 4%-6% of a lubricant, 6%-10% of an extreme pressure agent, 10%-15% of mixed alcohol amine, 4%-8% of an anti-rusting agent, 2%-4% of a pH (potential of hydrogen) stabilizer, 15%-25% of a surfactant, 1%-2% of a hard water stabilizer, 1%-3% of a coupling agent, 2%-4% of a sterilizing mildew preventive and the balance of water. The cutting fluid doesn't contain mineral oil, sulfur, phosphorus, chlorine, boron, phenol, formaldehyde, secondary amine, heavy metals, sodium nitrite and other poisonous and harmful substances and is environment-friendly. The cutting fluid has excellent extreme pressure performance for lubrication, rust prevention and corrosion prevention performance and hard water stability and long service life, and can meet requirements of cutting processing including turning, milling, boring, drilling, tapping and the like of various titanium alloys, the titanium alloy processing efficiency can be improved by 40%, and the service life of a cutting is prolonged by 30%.