Flute grinding is a crucial process in solid end-mill manufacturing, because the generated flute parameters, i.e. helix angle, rake angle, core radius, and flute width, have significant effects on the cutting performance of end-mills. However, the flute grinding of non-cylindrical solid end-mills is still challenging due to the variable flute parameters along the tool axis. This paper proposes an accurate and efficient method of wheel path planning for flute grinding of non-cylindrical solid end-mills based on circular arc projection. The wheel path determined by the new method can accurately generate the designed variable helix angle, variable rake angle, variable core radius, and variable flute width. The rake angle is guaranteed by the conjugate condition between the wheel surface and the cutting-edge curve. Equivalent errors of core radius and flute width are introduced in this work based on circular arc projection. The accuracy of the two parameters is ensured by minimizing the sum of squares of the two equivalent errors. Simulations and experiments are conducted to validate the method. Three types of non-cylindrical end-mills i.e. tapered end-mill, tapered barrel end-mill, and barrel end-mill, are considered in the validation. The measured results indicate that the generated flute parameters coincide well with the designed ones at different axial positions of the end-mills.