要加快AWS预签名URL下载的速度，可以尝试以下方法：

1. 使用多线程下载：通过创建多个线程来同时下载文件，可以提高下载速度。下面是一个使用Python的示例代码：

import threading
import requests

def download_part(url, start, end, part_num):
    headers = {'Range': 'bytes={}-{}'.format(start, end)}
    response = requests.get(url, headers=headers)
    with open('part{}.bin'.format(part_num), 'wb') as file:
        file.write(response.content)

def download_file(url, num_parts):
    response = requests.head(url)
    file_size = int(response.headers['Content-Length'])
    part_size = file_size // num_parts

    threads = []
    for i in range(num_parts):
        start = i * part_size
        end = start + part_size - 1 if i < num_parts - 1 else file_size - 1
        thread = threading.Thread(target=download_part, args=(url, start, end, i))
        thread.start()
        threads.append(thread)

    for thread in threads:
        thread.join()

    with open('output.bin', 'wb') as file:
        for i in range(num_parts):
            with open('part{}.bin'.format(i), 'rb') as part_file:
                file.write(part_file.read())

        for i in range(num_parts):
            os.remove('part{}.bin'.format(i))

url = 'https://example.com/file'  # 替换为AWS预签名URL
num_parts = 4  # 设置线程数
download_file(url, num_parts)

2. 使用断点续传：如果中断了下载过程，可以使用HTTP的Range头部来继续下载。这样可以避免重新下载整个文件。下面是一个使用Python的示例代码：

import requests

def download_file(url):
    headers = {}
    if os.path.exists('output.bin'):
        headers['Range'] = 'bytes={}-'.format(os.path.getsize('output.bin'))

    response = requests.get(url, headers=headers, stream=True)
    with open('output.bin', 'ab') as file:
        for chunk in response.iter_content(chunk_size=1024):
            file.write(chunk)

url = 'https://example.com/file'  # 替换为AWS预签名URL
download_file(url)

3. 使用更快的网络连接：如果下载速度仍然很慢，可能是由于网络连接较差。尝试使用更快的网络连接或连接到更近的AWS区域。

使用上述方法之一，您应该能够加快AWS预签名URL的下载速度。请注意，下载速度还会受到网络状况和服务器响应速度的影响。