A parallel core simulation device for commingling production in low-permeability gas reservoirs includes a gas supercharger configured to provide a high pressure gas to simulate a fluid in a gas reservoir, a plurality of core holders arranged in parallel, a thermostat configured to control a temperature of each core holder to simulate a temperature of the gas reservoir, a pressure pump configured to control a pressure applied to each core holder to simulate a confining pressure of the gas reservoir, a first back-pressure valve communicated with each core holder, a fully-automatic gas meter configured to measure a rate and a volume of gas production and a second hydraulic pump configured to simulate a part of a gas well Christmas Tree.