Traditional schemes for multistep resonance photoionization of atoms let every employed laser beam interact with the atoms simultaneously. In such a situation, analyses via time-dependent Schr\"odinger equation show that high ionization probability requires all the laser beams must be intense enough. In order to decrease laser intensity, we proposed a scheme that the laser beam used to pump the excited atoms (in a higher bound state) into an autoionization state does not interact with the atoms until all the population is transferred by the other lasers from a ground state to the bound state. As an interesting example, we examined three-step photoionization of ${}^{235}\mathrm{U}$ with our scheme, showing that the intensity of two laser beams can be lowered by two orders of magnitude without losing high ionization probability.Traditional schemes for multistep resonance photoionization of atoms let every employed laser beam interact with the atoms simultaneously. In such a situation, analyses via time-dependent Schr\"odinger equation show that high ionization probability requires all the laser beams must be intense enough. In order to decrease laser intensity, we proposed a scheme that the laser beam used to pump the excited atoms (in a higher bound state) into an autoionization state does not interact with the atoms until all the population is transferred by the other lasers from a ground state to the bound state. As an interesting example, we examined three-step photoionization of ${}^{235}\mathrm{U}$ with our scheme, showing that the intensity of two laser beams can be lowered by two orders of magnitude without losing high ionization probability.

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{}^{235}\mathrm{U}

with our scheme, showing that the intensity of two laser beams can be lowered by two orders of magnitude without losing high ionization probability.