The past few years have witnessed an exponential growth of diverse Internet of Things (IoT) devices as well as compelling applications ranging from industrial production, intelligent transport, warehouse logistics to medical care. Dramatic advances in IoT technology not only bring enormous economic opportunities but also challenges. Recently, the integration of IoT and blockchain (BCoT) is considered a promising solution . Blockchain technology provides a secure and scalable framework to improve the data management of IoT devices. However, the huge computation and energy consumption in the blockchain consensus process prevents it from being directly applied as a generic platform for IoT. In this paper, we propose a cloud mining pool-aided BCoT architecture. The IoT devices can rent the computation resource from the cloud services dynamically. Then, the individual cloud miners are grouped into several mining pools to share block rewards to earn a steady profit and reduce the income variance. Based on this architecture, we study the mining pool selection problem and analyze the colony behaviors of IoT devices. We propose a centralized evolutionary game-based pool selection algorithm. In addition, considering the non-cooperative relationship among multiple miners, we also propose a lightweight distributed reinforcement learning algorithm, named the WoLF-PHC algorithm.