Cavity　method　is　widely　used　in　microwave　measurement　of　electromagnetic　properties.　In　this　research,　a　new　double-ridged　cavity　method　is　proposed,　which　can　enhance　the　operational　frequency　bandwidth.　Based　on　the　perturbation　theory,　the　measurement　equations　required　for　permittivity　and　permeability　extraction　are　developed.　And　for　the　accurate　obtaining　of　electromagnetic　properties,　a　calibration　method　is　introduced　to　calibrate　the　shape　factors.　The　proposed　method　is　firstly　simulated　using　the　High　Frequency　Structure　Simulator　(HFSS)　to　demonstrate　the　linear　relationship　between　the　resonant　parameters　and　the　electromagnetic　properties.　Thereafter,　a　series　of　standard　samples　are　tested　by　using　the　numerical　simulation.　Compared　with　the　reference　data,　the　calibration　method　can　obviously　improve　the　accuracy　of　electromagnetic　parameters.　Especially　the　error　of　the　imaginary　part　in　complex　permeability　is　reduced　front　more　than　60%　to　about　4%.　©　2019　IEEE.