The invention discloses an unconventional oil and gas reservoir fracturing method based on a liquefied petroleum gas. The unconventional fracturing transformation method comprises the following steps: pressing low-temperature liquefied petroleum gas fracturing fluid into the oil and gas reservoir though a high-pressure pump system, fracturing the reservoir under high pressure, enabling the low-temperature liquefied petroleum gas fracturing fluid to absorb heat in the reservoir to expand, and further fracturing the reservoir; then, introducing a supporting agent into the reservoir by the cross-linked fracturing liquid; after fracturing, gasifying and returning the fracturing liquid, recycling and separating for reusing. Additives of a cross-linking agent, the supporting agent and the like are added into the fracturing liquid through a normal-pressure online mixing mode, so that an external stirring device is cancelled, and large-scale continuous fracturing construction can be realized.