An insulation structure of catalytic converter of vehicle according to an exemplary embodiment of the present invention includes an LNT converter. A connecting housing is provided such that a urea reducing agent is injected to the exhaust gas when it is needed. An SDPF converter reduces nitrogen oxide contained in the exhaust gas using the injected reducing agent, and SCR catalyst is coated on a filter. An insulation cover including inner surface contacts the LNT converter, the connecting housing and the SDPF converter and also includes an outer surface which is opposing surface to the inner surface and surrounds the LNT converter, the connecting housing and the SDPF converter. The insulation cover insulates heat generated from the LNT converter, the connecting housing and the SDPF converter. An insulation material is inserted and attached between the outer surface and the inner surface of the insulation cover.