Butyl sound deadening sheet extrusion coater, designed for introducing shock-absorbing and sound-insulating properties on substrates via coating, comes with an automatic cutting device and auxiliary winding device. Mainly suitable for butyl sealing rubber strip, vibration and sound insulation board, etc. An automatic edge correcting system is featured, and a specially designed applicator head flow channel ensures uniform rubber coating. High automation and easy operation contribute to labor reduction, thus cost reduction.