Stream cipher salsa20 is one of the seven finally victor algorithms of Estream stream cipher project. An algebraic truncated differential cryptanalysis of 5-round Salsa20 based on solving nonlinear equations and two higher differential characteristics for 3-round Salsa20 is shown, with the computational complexity of O(2¹⁰⁵), the date complexity of O(2¹¹), the space complexity of O(2¹¹). It also has a success rate of 97.72%, and holds the best result of analysis of 5-round Salsa20 by now.