一种可能的方法:

function getContents($str, $startDelimiter, $endDelimiter) {
  $contents = array();
  $startDelimiterLength = strlen($startDelimiter);
  $endDelimiterLength = strlen($endDelimiter);
  $startFrom = $contentStart = $contentEnd = 0;
  while (false !== ($contentStart = strpos($str, $startDelimiter, $startFrom))) {
    $contentStart += $startDelimiterLength;
    $contentEnd = strpos($str, $endDelimiter, $contentStart);
    if (false === $contentEnd) {
      break;
    }
    $contents[] = substr($str, $contentStart, $contentEnd - $contentStart);
    $startFrom = $contentEnd + $endDelimiterLength;
  }

  return $contents;
}

用法:

$sample = '<start>One<end>aaa<start>TwoTwo<end>Three<start>Four<end><start>Five<end>';
print_r( getContents($sample, '<start>', '<end>') );
/*
Array
(
    [0] => One
    [1] => TwoTwo
    [2] => Four
    [3] => Five
)
*/ 

演示 .