SOURCE

var poly1 = turf.polygon([
    [
    [
    118.544694359,
    29.394588189000004
    ],
    [
    118.542326689,
    29.336553810999973
    ],
    [
    118.48461473699999,
    29.363640637000017
    ],
    [
    118.544694359,
    29.394588189000004
    ]
    ]
]);
var poly2 = turf.polygon([
    [
    [
    118.5070832918744,
    29.382919780030406
    ],
    [
    118.58900198228223,
    29.393880267726317
    ],
    [
    118.542326689,
    29.336553810999973
    ],
    [
    118.5070832918744,
    29.382919780030406
    ]
    ]
]);
var geojson = turf.intersect(poly1, poly2) 

var polygon = new ol.geom.Polygon(geojson.geometry.coordinates);

var feature = new ol.Feature(polygon);

var vectorSource = new ol.source.Vector();
vectorSource.addFeature(feature);

var vectorLayer = new ol.layer.Vector({
    source: vectorSource
});

const berlin = new ol.Feature({
  geometry: new ol.geom.Point([118.544694359,29.394588189000004]),
});

berlin.setStyle(
  new ol.style.Style({
    text: new ol.style.Text({
        // text: '北京市昌平区回龙观',
        font: '14px sans-serif',
        offsetX: 16,
        fill: new ol.style.Fill({
          color: 'black',
        }),
        textAlign: 'left',
        padding: [2, 3, 0, 2],
        backgroundFill: new ol.style.Stroke({
          color: '#fff'
        }),
        backgroundStroke: new ol.style.Stroke({
            color: 'black',
            width: .5,
            lineCap: 'butt',
            lineJoin: 'bevel',
            lineDash: [0]
        })
    }),
    image: new ol.style.Icon({
        crossOrigin: 'anonymous',
        // imgSize: [20, 20],
        scale: .14,
      src: 'http://cdn.jsrun.top/res/kelee/crood.png',
    }),
  })
);
setTimeout(() => {
    berlin.setStyle(
        new ol.style.Style({
            text: new ol.style.Text({
                text: '北京市昌平区回龙观',
                font: '14px sans-serif',
                offsetX: 16,
                fill: new ol.style.Fill({
                color: 'black',
                }),
                textAlign: 'left',
                padding: [2, 3, 0, 2],
                backgroundFill: new ol.style.Stroke({
                color: '#fff'
                }),
                backgroundStroke: new ol.style.Stroke({
                    color: 'black',
                    width: .5,
                    lineCap: 'butt',
                    lineJoin: 'bevel',
                    lineDash: [0]
                })
            }),
            image: new ol.style.Icon({
                crossOrigin: 'anonymous',
                // imgSize: [20, 20],
                scale: .14,
            src: 'http://cdn.jsrun.top/res/kelee/crood.png',
            }),
        })
    );
}, 3000)

vectorSource.addFeature(berlin);
var map = new ol.Map({
    target: 'map',
    layers: [
        new ol.layer.Tile({
            source: new ol.source.OSM()
        }),
        vectorLayer
    ],
    view: new ol.View({
        projection: 'EPSG:4326',
        center: [118.542026689, 29.364503810999973],
        zoom:13
    })
});

<div id="map" class="map"></div>

.map {
    height: 600px;
    width: 100%;
}