The surface configuration, the size and the shell thickness of the microcapsule were investigated. The average size and shell thickness were 100-200μm and 10nm separately. The mechanism performance of the microcapsule was tested by Nano Indentation Test. The results showed that the shell material—UF behaved as a non-linear viscoelastic material that different from the macroscopical performance. Analyzed and computed the un-load curves by non-linear simulation, the results showed that Educed Modulus of the microcapsule was 8.201GPa, which was a little lower than that of the epoxy resin 9.26GPa. And it also proved that the self-repair microcapsule in the epoxy resin dope would break as the microcrack expanded in the matrix, and let out the repair agent to fill the crack and to recover the matrix.