您可以使用before和after伪元素来创建模糊图像和非模糊文本覆盖，该覆盖完全适合模糊背景。
使用filter: blur()模糊背景。以及-webkit-background-clip: text;和-webkit-text-fill-color: transparent;来创建文本覆盖，该文本覆盖具有与背景填充相同的图像锐化版本。

.blur {
    position: relative;
    overflow: hidden;
    height: 500px;
    width: 800px;
}

.blur:before {
    content: '';
    display: block;
    position: absolute;
    height: 100%;
    width: 100%;
    background: url('https://images.bonnier.cloud/files/his/production/2022/03/06155010/Picasso-FB.jpg?max-w=1200&max-h=630&fit=crop') center;
    background-size: cover;
    filter: blur(18px);
}

.blur:after {
    content: 'BLUR';
    position: absolute;
    height: 100%;
    width: 100%;
    font-family: Roboto, 'Helvetica Neue', Arial, sans-serif;
    text-transform: uppercase;
    font-size: 260px;
    font-weight: bold;
    text-align: center;
    padding: 100px 0;
    box-sizing: border-box;
    background: url('https://images.bonnier.cloud/files/his/production/2022/03/06155010/Picasso-FB.jpg?max-w=1200&max-h=630&fit=crop') center;
    background-size: cover;
    color: white;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

<div class="blur"></div>