Multi-span plastic Greenhouse:Films for covering materials, multi-form structure. According to the different climatic conditions, planting target and function, it can be built up single Films Greenhouse and double-layer films greenhouse. Hot zinc-plated steel type material for framework, top or side of greenhouse is covered with import or homemade films. The films greenhouse is extremely popular at home and is mostly middle-low grade greenhouses. As regards area, our country has already leapt to the first in the world. The films greenhouse is of simple structure, cheap cost, short time limit for a project and strong applicability. The shortcoming of this type is fast attenuation of light transmittance, not ageing-resistant and short-lived.