The invention discloses a deep hole blasting charging method for passing through a solution cavity and a solution cavity detecting device. A deep hole comprises an upper blast hole section and a lowerblast hole section. A middle solution cavity exists between the upper blast hole section and the lower blast hole section, and the position and depth of the middle solution cavity are obtained through detection. In the upper blast hole section, a hole opening blocking section, upper section explosives and a solution cavity upper section blocking section are sequentially arranged from a hole opening to the hole bottom. In the lower blast hole section, the lower half section is filled with lower section explosives, and the upper half section is the solution lower section blocking section and blocks a hole opening of the lower blast hole section. A detonating cord communicates between the upper section explosives and the lower section explosives. According to the deep hole blasting chargingmethod, the blocking structure close to the middle solution cavity is utilized for carrying out delaying explosion to cause gas expansion, gas is extruded into the solution cavity to fill the solutioncavity after the upper section explosives and the lower section explosives are exploded, explosive energy leakage is effectively avoided, and the rock breakage effect is improved; and the remarkableadvantages of being convenient to construct, environment-friendly, efficient and economical are achieved.