In this paper, we develop an algorithm to solve nonlinear system of monotone equations, which is a combination of a modified spectral PRP (Polak-Ribière-Polyak) conjugate gradient method and a projection method. The search direction in this algorithm is proved to be sufficiently descent for any line search rule. A line search strategy in the literature is modified such that a better step length is more easily obtained without the difficulty of choosing an appropriate weight in the original one. Global convergence of the algorithm is proved under mild assumptions. Numerical tests and preliminary application in recovering sparse signals indicate that the developed algorithm outperforms the state-of-the-art similar algorithms available in the literature, especially for solving large-scale problems and singular ones.It has been shown that the solution set of problem (1) is convex if it is nonempty [3]. In addition, throughout the paper, the space is equipped with the Euclidean norm ‖ ⋅ ‖ and the inner product ⟨ , ⟩ = , for , ∈ . Aiming at solution of problem (1), many efficient methods were developed recently. Only by incomplete enumeration, we here mention the trust region method [19], the Newton and the quasi-Newton methods [4][5][6]19], the Gauss-Newton methods [7,8], the Levenberg-Marquardt methods [20][21][22], the derivative-free methods and its modified versions [9][10][11][12][13][14][15][16][23][24][25][26][27], the derivative-free conjugate gradient projection method [14], the modified PRP (Polak-Ribière-Polyak) conjugate gradient method [11], the TPRP method [10], the PRP-type method [28], the projection method [23], the FR-type method [9], and the modified spectral conjugate gradient projection method [13]. Summarily, the spectral Hindawi