The　low　permeability　of　coalbed　methane　(CBM)　reservoirs　restricts　the　efficient　extraction　of　CBM.　Organic　solvent　erosion　is　a　sound　method　to　improve　the　permeability　of　coal;　however,　a　nondestructive　testing　(NDT)　method　for　identifying　the　effects　of　erosion　on　coal　is　necessary.　The　ultrasonic　characteristics　of　coal　can　reflect　the　physical　state　of　coal;　therefore,　ultrasonic　testing　is　a　suitable　method　for　identifying　the　erosion　effect.　First,　the　characteristics　of　fracture　development　in　coal　were　studied　through　surface　observations　and　mass　analysis.　Organic　solvent　treatment　is　an　effective　means　to　promote　the　development　of　coal　fractures,　and　the　effects　of　organic　solvent　erosion　on　coal　can　be　divided　into　three　grades.　The　effects　of　organic　solvent　erosion　on　coal　are　influenced　by　the　extraction　rate　of　the　solvent　for　coal.　A　high　extraction　rate　can　improve　the　degree　of　coal　fracture　development,　and　coal　becomes　susceptible　to　breakage.　N-Methylpyrrolidone　(NMP)　and　tetrahydrofuran　(THF)　have　high　extraction　rates　for　coal　and　are　suitable　for　solvent　treatment.　Subsequently,　the　effects　of　solvent　erosion　on　the　ultrasonic　characteristics　were　comprehensively　investigated.　After　solvent　erosion,　the　ultrasonic　characteristics　of　coal　changed　remarkably.　The　peak　amplitude　of　the　time-domain　spectrum　decreased　by　13.5-56.7%,　the　ultrasonic　velocity　decreased　by　39.1-70.1%,　and　the　ultrasonic　attenuation　coefficient　increased　by　12.2-130.7　dB/m.　The　relationship　between　the　degree　of　erosion　and　ultrasonic　parameters　was　revealed,　and　the　physical　state　of　coal　was　deduced　through　the　ultrasonic　parameters.　Thus,　ultrasonic　detection　can　be　used　as　an　NDT　method　in　solvent　treatment.　These　results　provide　a　theoretical　basis　for　the　application　of　solvent　treatment　in　the　coal　industry.