Cavity　method　is　widely　used　in　microwave　measurement　of　electromagnetic　properties.　In　this　paper,　a　new　double-ridged　cavity　method　is　proposed,　which　can　enhance　the　operational　frequency　bandwidth.　Building　on　the　perturbation　theory,　the　measurement　equations　required　for　permittivity　and　permeability　extraction　are　developed.　And　for　obtaining　the　electromagnetic　properties　more　accurately,　a　calibration　method　is　introduced　to　calibrate　the　shape　factors.　The　proposed　method　is　first　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　also　tested　and　verified　by　using　the　numerical　simulator.　For　comparison　the　reference　data,　the　calibration　method　can　obviously　improve　the　accuracy　of　electromagnetic　parameters,　especially　the　imag　part　error　of　complex　permeability,　which　is　reduced　from　more　than　60%　to　about　4%.