The present invention relates to a plastic greenhouse heating device capable of adjusting and heating temperatures inside a plastic greenhouse so as to cultivate crops in the plastic greenhouse in all seasons. In order to cultivate crops on the basis of a plastic greenhouse having an area of 330 m^2, a geothermal exchanger (5) including three pairs of U-shaped geothermal exchange pipes (5a-5c) buried under the ground at 152 m where geothermal heat is maintained at 14 to 16°C is installed to maintain a temperature suitable for growing the crops inside the plastic greenhouse. Since a total length of the pipes of the geothermal exchanger (5) is 900 m, geothermal water passing the inside of the geothermal exchange pipes (5a-5c) adsorbs geothermal heat which is a pure new and renewable energy and the geothermal water, which is new and renewable energy, adsorbing the geothermal heat is pumped up to a spray nozzle (8) by a high pressure pump for spraying. The spray nozzles (8) are installed at intervals of 0.5 to 1 m along the ridge direction of the top part of a second plastic roof (2P) which is installed under a first plastic roof (1P) blocking external cold air. The geothermal water is sprayed by the spray nozzles (8) from the ridge part of the top of the second roof, so a water film is formed in the left and the right direction of the ridge part of the top. Thus, since an internal temperature of the plastic greenhouse is maintained at 7 to 12°C by the geothermal water of 14 to 16°C flowing on the second plastic roof (2P), the crops cultivated inside the plastic greenhouse can be normally grown even if season is changed.COPYRIGHT KIPO 2017시설작물재배 비닐 하우스의 면적 330㎡기준으로 농작물을 재배하기 위하여 비닐 하우스의 내부에서 성장할 수 있는 적합한 온도를 유지하기 위하여 지열이 14℃ 내지 16℃ 의 온도를 유지하는 지하 152m깊이로 이루어지는 3쌍의 ∪형의 지열 교환파이프(5a-5c)로 구비되는 지열교환기(5)를 형성하되, 상기 지열교환기(5)의 파이프의 총연장 길이를 900M를 형성하므로, 지열 교환파이프(5a - 5c) 내부를 통과하는 지열수는 순수한 신재생 에너지인 지열이 흡수되고,지열이 흡수된 신재생 에너지인 지열수는 분사용 고압 양수기에 의거 분사노즐(8)까지 양수되며, 상기 분사노즐(8)은
