Achieving the separation between diamond films and substrate is the precondition and foundation to the application as a self-freestanding form. The separation techniques in widespread use currently, for metal substrate based on stress mechanism and silicon substrate using chemical corrosion process, are considered to be only suitable for the diamond thick films with enough strength. However, However, it is still difficult to achieve complete stripping of the diamond film that with small thickness and relatively low strength. In this paper, Ti, Si and glass carbon substrates were selected to prepare ultra-thin diamond films by microwave plasma chemical vapor deposition (MPCVD) with CH₄/H₂ as the reaction source. The overall morphology, surface morphology, composition and stress state of the prepared diamond films are analyzed by SEM and Raman. The results show that the diamond film grown only on glass carbon substrate can be automatically peeled off to form a complete self-supporting film, and the crystal surface of the film grain is clear, and the film thickness is only 10 μm; Raman spectra reveal that the thin films have strong sharp diamond characteristic peaks, and the calculated residual stress is the lowest. Combined with the surface changes of glass carbon substrate before and after deposition, and the internal structure characterization of self-supported diamond film, it is preliminatively inferred that one-step growth of ultra-thin diamond film and self-supported stripping can be achieved on glass carbon substrate. It is mainly attributed to the continuous etching effect of hydrogen plasma on the film-base interface during the growth process, which weakens the binding force and the low residual stress during the cooling process ensures the structural integrity of ultra-thin diamond film. This work is expected to provide an new effective technique for the one-step growth and stripping of ultra-thin self-supported CVD diamond films.