The invention belongs to the technical field of in-vitro establishment of tissue engineering cartilages, more particularly to an experimental method for establishing tissue engineering cartilage in vitro by taking a knee-joint cartilage unit of a rabbit as a seed cell. The experimental method comprises the following steps of: taking a keen joint of a rabbit, repeatedly cutting the joint cartilage into fragmentized tissues, washing, removing supernatant away and putting in a sterile conical flask for later use; adding dispase and II-type collagenase into the conical flask according to 12mL DMEM-F12 culture solution / g cartilage, stirring and digesting to form a digested suspension solution; filtering and centrifuging the digested suspension solution, adding a primary chondrocyte culture solution to prepare a sterile chondrocyte suspension solution, and carrying out sodium alginate gel three-dimensional culture on the obtained cartilage unit to construct the tissue engineering cartilage. The invention has the beneficial effects that: the cartilage unit has stable form and multiplication situation in the in-vitro long-term culturing process, the physiological function of substrate ingredients, such as secreted II-type collagen, and the like is improved, and the effect of repairing cartilage injury by adopting a tissue engineering method is expectedly accelerated.