Aiming　at　the　irregular　and　uneven　feature　of　medical　time　series　data,　a　novel　algorithm　based　on　piecewise　slope　transformation　distance　for　short　time　series　similarity　measure　is　propose.　We　firstly　do　some　preprocess　based　on　algorithm　for　key　points　selected,　make　the　data　curve　to　zigzag　shape,　then,　we　measure　the　distance　between　two　curves　based　on　piecewise　slope　transformation　algorithm.　By　experiments,　conclusion　can　be　draw　that　this　new　approach　can　measure　distance　rapidly　and　correctly,　especially　appropriate　to　short　time　series　data.