The present invention discloses a flat-belt driven disc separator, comprising a power part, a driving part, a lubrication system, a working part, a machine part and a control and assisting part. In addition to that the requirements of the function and performance of the separator is satisfied, the driving system is largely simplified, the driving path is brief, the quantity of driving components is largely reduced and the technical requirement of processing is lowered; regular replacement of expensive copper gear wheel, friction drum and other wearing parts is avoided, and as a result, the structure of the complete machine is simplified, the cost of production and use is reduced, the failure rate of the machine is lowered, and the technical performance of the complete machine is improved. The invention can be directly applied to condensing separation of natural rubber, and the invention can also be applied to separating other emulsions; the rotary-drum structure of the invention can overcome the disadvantages of the prior art; the continuous operation time is prolonged and the rotary-drum heating is alleviated; the strength, safety, reliability and maintenance technique are improved. The driving part and the lower machine body can form the driving of a manual slag-discharge separator, a gushing slag-discharge separator and a ring-valve slag-discharge separator and the lower machine body.