<tr ng-if="$scope.colspan === 1">
    <td></td>
    <td></td>
    <td></td>
</tr>
<tr ng-if="$scope.colspan === 2">
    <td></td>
    <td></td>
</tr>
<tr ng-if="$scope.colspan === 3">
    <td></td>
    <td></td>
    <td></td>
</tr>

用angular>ng-if解决

随便猜了下你的想法。。

var json = [{
    colspan: 1,
    title: 1
}, {
    colspan: 2,
    title: 2
}, {
    colspan: 3,
    title: 3
}]

document.body.innerHTML = '<table>'+ generateTr(json) +'</table>'

function generateTr(json) {
    var tr = []
    for (var i = 0, l = json.length; i < l; i++) {
        var item = json[i],
            tds = []
        for (var j = 0, k = Math.ceil(3 / item.colspan); j < k; j++) {
            tds.push('<td' + (j == 0 ? ' colspan="' + item.colspan+'"' : '') + '>' + item.title + '</td>')
        }
        tr.push('<tr>' + tds.join('') + '</tr>')
    }
    return tr.join('')
}