Cooperative energy spectrum sensing has been proved effective to detect the spectrum holes in Cognitive Radio (CR). However, few studies make mention of wavelet transform based signal processing before energy detection. In this paper, a novel cooperative energy spectrum sensing algorithm with 1-D or 2-D wavelet denoising is proposed. The 1-D wavelet denoising is performed at each sensing node, while the 2-D wavelet denoising is implemented at the sensing station. Simulation results show that the spectrum sensing performance is improved significantly by the proposed cooperative spectrum sensing algorithm with wavelet denoising as opposed to the conventional method.