In order to enhance intensity of high-order harmonic spectrum and attosecond pulse, characteristics of high-order harmonic radiation of H+2 driven by pump probe laser were studied by numerical solution of Schrodinger equation. The results show that H+2 is excited into the multi-photon resonance ionization region at first and then increases the ionization probability under the pump laser. The harmonic radiation intensity is enhanced under the detection laser. The cut-off frequency of the harmonic wave can be further extended when the asymmetric non-uniform laser field is used. The energy peak contribution of single harmonic radiation is obtained. Finally, the pulse width of 32as can be obtained by superposing the harmonics of Fourier transform. This study is helpful for the generation of single attosecond pulses.