您可以将minZoom和maxZoom级别设置为1，如下所示：
var map = L.map('map', {
minZoom: 1,
maxZoom: 1,
});
然后定义setView，如下所示：
map.setView([0, 0], 0);
<!DOCTYPE html>
<html>
<head>
<title>Zoom Levels Tutorial - Leaflet</title>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="shortcut icon" type="image/x-icon" href="docs/images/favicon.ico" />
<link rel="stylesheet" href="https://unpkg.com/[email protected]/dist/leaflet.css" integrity="sha512-puBpdR0798OZvTTbP4A8Ix/l+A4dHDD0DGqYW6RQ+9jxkRFclaxxQb/SJAWZfWAkuyeQUytO7+7N4QKrDh+drA==" crossorigin=""/>
<script src="https://unpkg.com/[email protected]/dist/leaflet.js" integrity="sha512-QVftwZFqvtRNi0ZyCtsznlKSWOStnDORoefr1enyq5mVL4tmKB3S/EnC3rRJcxCPavG10IcrVGSmPh6Qw5lwrg==" crossorigin=""></script>
<style>
html, body {
height: 100%;
margin: 0;
}
#map {
width: 600px;
height: 400px;
}
</style>
</head>
<body>
<div id='map'></div>
<script>
var map = L.map('map', {
minZoom: 1,
maxZoom: 1,
});
var cartodbAttribution = '© <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors, © <a href="http://cartodb.com/attributions">CartoDB</a>';
var positron = L.tileLayer('https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', ).addTo(map);
map.setView([0, 0], 0);
</script>
</body>
</html>