composer require mikehaertl/php-pdftk

<?php
 require '/vendor/autoload.php';

 use mikehaertl\pdftk\Pdf;
 use mikehaertl\pdftk\FdfFile;

// 用数据数组填充表单
$pdf = new Pdf('form.pdf');
$pdf->fillForm([
        'name'=>'西贝小小凤',
        'sex' => '女',
    ])
    ->needAppearances()
    ->saveAs('filled.pdf');

// 从FDF填写表格 data.xfdf文件长啥样呢？看下面的代码 
$pdf = new Pdf('form.pdf');
$pdf->fillForm('data.xfdf')
    ->saveAs('filled.pdf');

// 检查错误
if (!$pdf->saveAs('my.pdf')) {
    $error = $pdf->getError();
}

use mikehaertl\pdftk\XfdfFile;
use mikehaertl\pdftk\FdfFile;

$xfdf = new XfdfFile(['name' => '西贝小小凤'，'sex' => '女']); 

$xfdf->saveAs('/path/to/data.xfdf'); 

$fdf = new FdfFile(['name' => '西贝小小凤'，'sex' => '女']);
$fdf->saveAs('/path/to/data.fdf');

<?xml version="1.0" encoding="UTF-8"?>
<xfdf xmlns="http://ns.adobe.com/xfdf/" xml:space="preserve">
<fields>
<field name="name">
<value>西贝小小凤</value>
</field>
<field name="sex">
<value>女</value>
</field>
</fields>
</xfdf>

pdftk a.pdf fill_form data.fdf output  b.pdf

pdftk 1.pdf output fixed.pdf

<?php

//引入文件
require('fpdm.php');
//数组数据填充，字段要对应pdf的表单字段
$fields = array(
    'name'    => '你好',
    'type'    => '1231',
);
//引入模板文件
$pdf = new FPDM('fixed.pdf');
$pdf->Load($fields, true); // second parameter: false if field values are in ISO-8859-1, true if UTF-8
$pdf->Merge();
$pdf->Output();//输出文件
?>

<?php
$aa = file_get_contents('http://localhost/fpdm/ex-array.php');//上面的ex_array.php文件
$myfile = file_put_contents("1122.pdf", $aa)//生成新的填充后的1122.pdf文件
?>