有些事情要尝试。
回复：我如何准确地循环一行降低每一次都为Parth编号和Leadtime？

Use ".Offset(3, 0).Select"

回复：未找到部件
将“单元格.查找（What：=“PartNum”）.偏移量（2，0）.选择”替换为：

Dim PN As Range
Set PN = Cells.Find(What:="PartNum")

If PN Is Nothing Then
    MsgBox ("Part Number is not found")
    'Exit Sub?
End If

PN.Offset(3, 0).Select

根据我所能收集到的从您张贴的代码，但需要一些澄清围绕什么你正在做的“出口”表...

Option Explicit

Sub CopyData()

    Dim wsQuote As Worksheet, wsExport As Worksheet, wb As Workbook
    Dim str1 As String, f As Range, f2 As Range
    
    'use an explicit workbook reference
    Set wb = ThisWorkbook 'or ActiveWorkbook for example
    Set wsQuote = wb.Worksheets("Quote")
    Set wsExport = wb.Worksheets("Export")

    Set f = FindWholeValue(wsQuote.Cells, "PartNum")
    If f Is Nothing Then Exit Sub
    
    str1 = f.Offset(2, 0).Value 'two rows down from "PartNum"

    '------------------
    'Can't figure out what you're doing on the Export sheet...
    '
    '  Set f2 = ???
    '------------------
    
    Set f = FindWholeValue(wsQuote.Cells, "Leadtime")
    If f Is Nothing Then Exit Sub
    
    f.Offset(2, 0).Value = f2.Value
    
End Sub

'Search `rng` for `v` and return the first matched cell
'If not found and `WarnIfMissing` is True, warn the user
Function FindWholeValue(rng As Range, v, Optional WarnIfMissing As Boolean = True) As Range
    Set FindWholeValue = rng.Find(what:=v, lookat:=xlWhole, LookIn:=xlFormulas)
    If FindWholeValue Is Nothing And WarnIfMissing Then
        MsgBox "Value '" & v & "' not found on sheet '" & rng.Parent.Name & "'"
    End If
End Function