Abstract: In the sense of the conformable fractional derivative, the fractional nonlinear partial differential equation is transformed
into an ordinary differential equation. By embedding univariate polynomial functions and bivariate polynomial functions with a coefficient of 1 into rational functions, respectively, 19 new exact solutions to the （3+1）-dimensional space-time fractional Yu-Toda-Sasa-Fukuyama equation are obtained, including 10 exponential function solutions, 3 rational function solutions, and 6 solutions involving logarithmic functions.

Key words: （3+1）-dimensional space-time fractional Yu-Toda-Sasa-Fukuyama equation, exact solution, conformable fractional
derivative, rational function, polynomial function