Heat radiation problem of a light emitting diode (LED) chip is a key point of the technology, and bad heat radiation can directly influence the service life and light efficiency of an LED, so that a large aluminum alloy die-casting heat radiating sheet is generally arranged on the upper part of an LED lamp, the LED is cooled down by utilizing the air convection, the size of the heat radiating sheet is larger when the power of the LED is greater, the cost by adopting a heat radiating pipe is high, for example, a streetlamp adopting the heat radiation way, dust and bird shit are accumulated in the heat radiating sheet as time goes by, the heat radiating effect is greatly reduced, and on the other hand a heat radiating substrate and a bonding material are critical for the heat radiation of the LED. The invention provides a light emitting diode (LED) heat radiating device and a streetlamp. The streetlamp consists of a lamp holder frame, an upper housing, a supporting plate and an LED bulb. By adequately utilizing different physical phenomena, combining the principles of calorifics and hydromechanics, the heat produced by the chip is brought away in time, a transient temperature field on the upper part of a heat guide plate is improved by utilizing the reverse thinking of the heat radiation, so that the airflow is accelerated, a rapid heat radiation effect can be realized, an energy-saving effect can be realized by utilizing a simple scientific principle, and the product can really realize a low-carbon, energy-saving, environment-friendly, high-quality and inexpensive effect.