The invention discloses a compressed sensing signal reconstruction method based on a conjugate gradient method. According to the invention, under the condition of known sensing matrixes and observed signals, the reconstruction of a source signal with sparsity under the white gaussian noise environment can be achieved by the conjugate gradient method. According to the compressed sensing signal reconstruction method, the deficiency that in the prior art the reconstruction method based on orthogonal matching pursuit is high in complexity and the deficiency that the prior art based on the gradient descent method is slow in rate of convergence and low in reconstruction accuracy are overcome, thus the source signal can be reconstructed with lower complexity and higher reconstruction accuracy in actual application.