The very small braking index of PSR J1734-3333, $n=0.9pm0.2$, challenges the current theories of braking mechanisms in pulsars. We present a possible interpretation that this pulsar is surrounded by a fall-back disk and braked by it. A modified braking torque is proposed based on the competition between the magnetic energy density of a pulsar and the kinetic energy density of a fall-back disk. With this torque, a self-similar disk can fit all the observed parameters of PSR J1734-3333 with natural initial parameters. In this regime, the star will evolve to the region having anomalous X-ray pulsars and soft gamma repeaters in the $P-dot{P}$ diagram in about 20000 years and stay there for a very long time. The mass of the disk around PSR J1734-3333 in our model is about $10M_{oplus}$, similar to the observed mass of the disk around AXP 4U 0142+61.
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