The exploration by the in-situ measurement in the stratosphere, approximately 8-50 km height, can be done by sounding balloons exclusively. The scientific sounding balloon was used in the past decades to carry up to tones of the scientific instruments to the upper atmosphere and reached a great contribution in the atmosphere science, space science, and astrophysics. But the large scientific balloon can be launched in the limited sites for the safety reason and its cost is not affordable by all scientists. By integrating the miniaturized sensors, processor board and meteorological sounding balloon, we developed an experimental platform to carry small instruments up to 33 km altitude and transmit data to mobile ground stations. This experimental platform has the advantages of lightweight, inexpensive, disposable, and safe. It is not only can be employed in the scientific measurement but also able to act as a testbed for the new technologies which is going to be used in sounding rocket or satellite missions. The system structure of this platform and a successful flight experiment are introduced in this paper, and the new possible improvement is also discussed.