var greenIcon = L.icon({
iconUrl: 'leaf-green.png',
shadowUrl: 'leaf-shadow.png',//阴影图标
iconSize: [20, 20], // 图标尺寸
iconAnchor: [0, 0], // 图标偏移
shadowSize: [50, 64], //阴影大小
shadowAnchor: [4, 62], //阴影大小
popupAnchor: [-3, -76]//popup偏移
});
//直接将maker添加到地图上
L.marker([51.5, -0.09], {icon: greenIcon}).addTo(map);