Superconducting circuits based on Josephson junctions are regarded as one of the most promising technologies for the implementation of scalable quantum computers.This review presents the basic principles of superconducting qubits and shows the progress of quantum computing and quantum simulation based on superconducting qubits in recent years.The experimental realization of gate operations,readout,error correction codes,as well as some quantum algorithms are summarized,followed by an introduction of quantum simulation.And then some important applications in fields including condensed matter physics,quantum annealing,and quantum chemistry are discussed.