layer = qgis.utils.iface.mapCanvas().currentLayer()
if layer.wkbType() == QGis.WKBPoint:
    print('Layer is a pojnt layer')
if layer.wkbType() == QGis.WKBLineString:
    print('Layer is a line layer')
if layer.wkbType() == QGis.WKBPolygon:
    print('Layer is a polygon layer')
if layer.wkbType() == QGis.WKBMultiPolygon:
    print('Layer is a multi-polygon layer')
if layer.wkbType() == 100:
    pass
how to get shapefile geometry type in PyQgis