| Based on the systematic study of the existed achievements and review of document, in combination with the theoretic analysis, simulation experiment and field application, the theories and technologies of exploration for hidden cavity and its safety control in metal mines have been studied in this paper. And some of achievements have been successfully applied in Changba Pb-Sn Mine and Xinqiao Pyrites Mine.The author suggests that the hidden cavity in metal mines can be explored with the Technology of Sonic Computerized Tomography. A case study is also provided to support it. From principles of wave theory and Huygens-F-renel, the law of sonic wave transmitting in the medium of ore-rock has been presented. And from 3D geometrical attenuation, stickiness absorption, heat exchange absorption, the attenuation character of sonic wave transmitting in the medium of ore-rock, and the special losing parameter-Q and its relationship with absorption coefficient has been presented.Owing to the status that signal is difficult to identify, difficult to separate from noise, and initial time is difficult to choose in sonic computerized tomography exploration, Tomgraphy arithmetic has been studied to improve interpretive precision. The technique, which combines travel-time tomography with amplitude-attenuation tomography and chooses initial time with Artificial Neural Network (ANN), is given. Meantime, a new method with signal sound to gain the standard sample was firstly introduced. Based on the Dephi and Power Builder, the software with self-adaptive modified feedforward and feedback BP Artificial Neural Network was developed. And its dealing process has been studied.Simulation experiments have been done to find the influence of cavity shape and size on the test results. The relationship between the resolution and the ratio (D/ λ )of cavity size to wave length has been determined.
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