A multi-program multiplexing/demultiplexing method and apparatus for preventing MPEG jitters from being generated in a digital broadcast, and a multi-program receiver using the multi-program multiplexing/demultiplexing apparatus are provided. The multi-program multiplexing method comprises: extracting a plurality of transport stream packets from a plurality of channel decoders; comparing a reference clock value of each transport stream packet with a system clock value latched by the reference clock value, and generating a system clock control value; inserting the system clock value into a local packet of each channel; and multiplexing a plurality of local packets of a plurality of channels and generating a multi-program packet.