The invention relates to the technical field of rare-earth permanent magnet materials, in particular to cerium-containing low-melting-point rare-earth permanent magnet liquid phase alloy, a permanent magnet comprising the liquid phase alloy and a production method of the permanent magnet. According to mass percent, the chemical formula of the liquid phase alloy is that (Cex,Nd1-x)y-Mz-Fe100-y-z, wherein 0.1<=x<=1.0, 0.04<=y<=0.9, 0<=z<=5, M is one or several of Co, Al, Cu, Ga, Nb, Mo, Ti, Zr and V. The liquid phase alloy is added in an alloy or rapid hardening mode, cerium elements entering the principal phase can be reduced and the residual magnetism can be improved by aid of scientific and reasonable composition design, the sintering temperature of the neodymium iron boron magnet can be reduced through the low-melting-point liquid phase, and therefore low-temperature sintering is achieved, and reducing of the crystal grain dimension of the magnet is benefited. The microstructure of the liquid phase is controlled through the oxygen content so that the liquid phase is ensured to be of a cerium-containing face-centered cubic structure with high coercivity, further the coercivity of the magnet is improved, and good combination property can be obtained.