The invention discloses a liquid level meter for an isooctane flash tank. The liquid level meter comprises a flash tank body; an upper fluid outlet and a lower fluid outlet are formed in one side of the flash tank body, one ends of the fluid outlets communicate with a fluid flexible pipe, the other end of the fluid flexible pipe communicates with a buffer tube, and the other side of the buffer tube communicates with a liquid level meter body; and an elastic connector is connected between the flash tank body and the buffer tube, and the elastic connector sleeves the fluid outlets and the fluidflexible pipe. The problem that the display value of the liquid level meter body fluctuates up and down is effectively solved, the vaporization degree of a liquefied hydrocarbon fluid in the flash tank body is convenient to real-timely master and control, and thus isooctane production is facilitated.