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The most fascinating dibaryon in the non-strange quark sector is $$d^*(2380)$$, which was reported by WASA-at-COSY Collaboration and confirmed by A2@MAMI Collaboration. The reported mass and decay width are $$M\approx 2.37$$ GeV, $$\Gamma \approx 70$$ MeV and the quantum numbers are $$IJ^P=03^+$$. The structure of $$d^*(2380)$$ is still in controversy. In the present calculation, the powerful method in few-body system, Gaussian expansion method (GEM) is employed to explore the structure of $$d^*(2380)$$ in the framework of constituent quark models without assuming the presupposed structure. The results show that the radius of $$d^*(2380)$$ is around 0.8 fm, it is a very compact object. Because of the compact structure, the color singlet-singlet component has a large overlap with the color octet-octet one, two colorless, large overlapped $$\Delta $$s dominate the state is possible