The weak inertia support and strong stochastic fluctuations of high-proportion renewable energy power systems make it difficult to ensure the frequency quality of the power grid. Introducing different types of frequency regulation resources to participate in automatic generation control (AGC) is an effective way to handle the above problem, but it also requires that the AGC command allocation can adapt to the differentiated characteristics of different frequency regulation resources. To address this issue, a two-stage allocation method for AGC command with multi-resource coordination is proposed. First, different types of resources are arranged into the proactive AGC allocation stage or the real-time AGC allocation stage that matches their characteristics. Second, in the real-time allocation stage, an AGC command allocation strategy based on the allocation priority of resources is proposed. The allocation priority is designed according to the regulation characteristics of different resources and the frequency status of power systems. In this way, the superiority of different resources can be complementally utilized. Third, in the proactive allocation stage, an optimal allocation model is established to achieve the coordinately optimal utilization of different resources. The penalty terms related to the residual regulation redundancy of regulation resources are embedded to ensure the persistence of the frequency regulation ability of resources. Finally, case studies based on practical power grid data verify the effectiveness of the proposed method.