Diamane, as a recently synthesized two-dimensional nanomaterial, has excellent physical properties and enormous application prospects in the field of nano mass sensors. Based on molecular dynamics simulations and continuum theory, this article systematically studied the vibration characteristics of diamane nanosheet with attached mass. The results are compared with those of single-layer graphene nanosheet. It is found that the natural frequencies of diamane and single-layer graphene decrease with increasing attached mass. Under the same size, diamane has higher mass sensitivity than single-layer graphene. Pre-strain has a significant impact on the natural frequency of the structure. Increasing pre-strain can significantly increase the natural frequency of diamane and enhance their sensitivity. The position of the attached mass also affects the natural frequency. When it is close to the middle, the frequency shift reaches its maximum value, while when the attached mass is close to the fixed edge, it has almost no effect on the natural frequency.